CA1123813A - Aluminosilicate powders - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE
A porous powder composition useful as a catalyst having an amorphous aluminosilicate coating and a specific surface area of 30 to 750 m2/g, a bulk density of 0.5 g/cc or more with substantially uniform sized pores of a dia-meter within the range from 20 .ANG. to 150 .ANG., where 90% of the pore volume is of pores of from 0.6D to 1.4D where D is the median diameter of the pores, is prepared by a process com-prising (1) preparing a sol of discrete colloidal particles of uniform size within the range of from 2 to 87 nanometers, the surface of the particles consisting of a coating of an aluminosilicate at least 0.5 nanometer in thickness, by separately and simultaneously adding a sol of silica or a solution of sodium or potassium silicate and a solution of sodium or potassium aluminate to a heel sol of uniform-sized colloidal particles of aluminosilicate, silica, or one or more refractory metal oxides at a constant pH in the range of 9 to 12 and a temperature of 50 to 100°C to deposit or coat aluminosilicate onto the surface of the heel sol particles, (2) ion exchanging the sodium or potassion ions of the sol from (1) for ammonium ions, (3) optionally re-moving the ammonium ions partially or completely or ex-changing the ammonium ions partially or completely with one or more metal ions described herein selected from Groups I
to VIII of the Periodic Table, and (4) removing water from the sol without gelling so that the particles become uni-formly packed into aggregates having pores of substantially uniform size and coating said powder with a surface layer 0 to 15% by weight of a metal or metal oxide.

Description

BACKGF~OUND OF THE INVENTION
~ . . _ 1. Field of the Invention This invention relates to porous powders with an aluminosilicate coating with pores of substan-tially uniform size especially use~ul in the field of catalysis. ~ore specifically, this invention relates to porous powders hav-ing an aluminosilicate coating and a substantially uniform pore size, and a process comprising their preparation by drying to a powder without gelling an aluminosilicate aqua-sol having particles of uniform size.2. Prior Art Silica gels which are dried to porous silica powders are considered to be masses of spheres of sio2 ranging from a few Angstroms up to several hundred Angstroms in diameter, which are aggregated together in a three-dimensional mass. Vysotskii ["Adsorption and Adsorbents"
(No. 1), John Wiley & Sons, N.Y., 1973, p. 101] states that globular particles of silica form the skeleton of gels and that the cavities between the spherical particles ccnsti-tute the pores in silica gels. This structure of silicagels is further described in detail by R. X. Iler, "The Colloid Chemistry of Silica and Silicates", Cornell Uni-versity Press, Ithaca, N.Y., 1955, p. 129. The pore size and pore uniformity of silica is related to the particle size and particle uniformity.
U.S. Patent 3,782,075 discloses a silica packing material for chromatographic columns having uniform-sized porous microspheres having substantially all of the micro-spheres in the range of from 0.5D to 1.5D where D is the average diameter.

- 2 -

3~3 It is known to react sodium silicate, sodi-lm aluminate, and an acid, or sodium silicate, aluminum sul-fate, and an acid to form a gel or precipitate of alumino-silicate directly. However, the prior art does no-t teach any method for controlling the ultimate size of alumino-silicate particles which eventually aggregate to form the gel structure or the preparation of the ultimate particles of uniform size. The control of the pore size distribution, namely the size distribution of spaces between these pri-mary globules or aluminosilicate particles is likewise not known.
The difficulty of making aluminosilicate sol particles from which uniformly porous gels and powders can be formed is exemplified by Kontorovich, et al., J. of Colloid Chemistry, USSR (English translation), Vol. 35, p. 864, 1973 (Kolloyd, zhur, p. 935). Aluminosilicate particles,made simply by mixing sodium silicate, sulfuric acid, and aluminosulfate,showed a wide distribution of radii such that, for example, where the commonest particle radius was 20 A, a large fraction of the particles were also as large as 60 A radius. He further points out that even when the gels are aged for growth, the particles grow only to about 35 A, even after long exposure in water at 70C. He states definitely that the presence of aluminum in the globules hinders the increase in the size of the particles. This puts a limit in the Al content for certain particle sizes.
The nonuniformity of pores of amorphous alumino~
silicates is exemplified in U.S. Patent 3,346,509 which dis-closes the preparation of silica-alumina compositions with ~3~3 a preponderance of the pore volume in pores oE small radii.
The pore radii are disclosed as ranging from above 200 A
to less than 10 A with up to abou-t 60~ in the range of O O
10 A to 20 A.
U.S. Patent 3,766,057 discloses an alumino-silica gel dried to a powder having a mean pore radius of 40 A to 100 A and 15% of the pore volume in a 10 A section with a wide distribution of particles in the adjacent particle sizes.
Making aluminosilicate sols of particles of 3 to 150 millimicrons in diameter which are uniform in chemical composition was described by G. B. Alexander in U.S. Patent 2,974,108, issued March 7, 1961. In U.S. Patent 2,913,419, issued November 17, 1959, Alexander discloses the prepara-tion of gels and particles having a skin or outer surface of aluminosilicate composition. The gels have a coarse structure to permit coating with aluminosilicate without closing the pores in the gel. There is no disclosure of the need for uniform pores or for the preparation of uni-form pore sizes. Alexander's particles are used as filters while his gels are used as catalysts.
In porous catalyst powders, the uniformity in pore size is a definite advantage in affording specificity of reaction by avoiding side reactions and preventing the deposition of carbonaceous residues. Heretofore, it has not been possible to produce amorphous aluminosilicate catalysts with a uniform pore size.

SUMMARY OF THE INVENTION
Now it has been found that aluminosilicate porous powders with uniform pore size distribution comprising spheroidal colloidal particles of uniEorm size can be pre-pared by mixing the reactants of this invention at a con-stant pH to obtain a uniform particle siæe sol and drying said uniform particle size sol without ~elling.
The compositionsof this invention, which are particularly useful as a catalyst, consist essentially of uniformly porous powders comprising spheroidal colloidal particles of uniform size packed into porous aggregates having a uniform pore diameter between the particles, a bulk density of 0.5 g/cc or more, preferably from 0.5 to 0.9 g/cc and a specific surface area of 30 to 750 m2/g of said particles having a surface of amorphous aluminosilicate.
The uniform spheroidal discrete colloidal particles of the sol to be dried must be uniform in size and in the range from 3 to 90 nanometers.
The spheroidal particles have a coating that con-sists of an amorphous aluminosilicate. Said aluminosilicate is coated or deposited on a pre-formed core of more or less spheroidal colloidal particles which may or may not have the ~ same composition as the deposited aluminosilicate. For catalytic activity it is only essential that the required colloidal particles have a coating or surface of cataly-tically active amorphous aluminosilicate. This coating composition extends within the surface to a depth of at least 0.5 nanometer, preferably 0.5 to 1.5 nanometers.
Although this composition can extend to a depth of greater than 1.5 nanometers, depths greater than 1.5 nanometers are seldom required.
' The spheroidal particles are coated with an amor-phous hydrous aluminosilicate compound comprising one or more cations selected from the group consisting of sodium, potassium, hydrogen, ammonium and Group I to VIII metals selected from the group consisting of Cs, Li, Rb, Th, Mg, Ca, Sr, Ba, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, La, Ce, rare earth metals, Hf, Ta, W, Re, Os, Ir, Pt, Au, Sn, Cd, Bi and Sb. The interior of the spheroidal particles is also composed of said aluminosili-cate except to the extent that the nuclei or core may be a refractory metal oxide or silica.
The aluminosilicate chemical composition may be defined by the following formula:

x [(A1O2)X(Sio2)y]n.wH2o where x and y are the number of moles of AlO2 and SiO2 respectively, the molar ratio of y:x being from 1:1 to 1~:1 of Si:A1, and w is the moles of bound water, M is one or more metal cations selected from the group consisting of Na, Li, K, H, NH4, Cs, Rb, Th, Mg, Ca, Sr, Ba, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, La, Ce, rare earth metals, Hf, Ta, W, Re, Os, Ir, Pt, Au, Sn, Cd, Bi and Sb; and v is the valence of M. It is understood that where there are, e.g., three metals, the term Mx would include each metal and its valence. The cations represented by M are preferably selected from one or more of the group consisting of ammonium, hydrogen, Cs, ~i, Mg, Ca, Sr, Ba, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, La, Ce, rare earth metals, Hf, Ta, W, Re, Os, Ir, Pt, Au, Sn, Cd, Bi and Sb. What is meant by one or more is that in the replacement of sodium or potassium with one or more metal cations listed, there will be replacement to the extent the sodium or potassium is replaceable with one or more metal cations. Thus in addition to the one or more metal cations, some unreplaced sodium or potassium will remain.
Generally the aluminosilicate of this invention is produced in the form where M is sodium or potassium.
The sodium or potassium aluminosilicate is ion exchanged so that it is largely ammonium aluminosilicate although some sodium or potassium aluminosilicate still remains.
The ammonium aluminosilicate can be heated to drive off the ammonium to give hydrogen aluminosilicate. The final form of the powder is generally ammonium or hydrogen alumino-silicate. However, where it is desired to replace the ammonium or hydrogen with one or more metals indicated above for M, the sol before drying may be ion exchanged to yield the aluminosilicate with the desired metal or metals. In such a case, a small amount of ammonium and~or hydrogen aluminosilicate also remains.
The powder compositions of this invention may also have a surface layer over the aforesaid aluminosilicate coating of one or more of the following metal or metal oxides which may be in the cationic form, partially replac-ing M: Li, Cs, Rb, Mg, Ca, Sr, Ba, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, La, Ce, the rare eath metals, Hf, Ta, W, Re, Os, Ir, Pt, Cu, Ag, Th, Au, Sn, Cd, Bi and Sb. The most preferred aluminosilicate chemical com-position is where M is ammonium or hydrogen or mixtures thereof.
Thus, in accordance with the invention, a uni-formly porous powder composition has been found which com-prises porous aggregates of spheroidal particles which are 3 to 90 nanometers in size and nonporous to nitrogen and contain:
(a) a core of silica, aluminosilicate or one or more refractory metal oxides selected from alumina, zir-conia, titania, thoria and rare earth oxides;
(b) a coating around said core of at least 0.5 nanometer in depth of an amorphous hydrous aluminosilicate compound having a molar ratio of Si:Al of from l:l to 19:1 and comprising one or more cations selected from sodium, potassium, ammonium, hydrogen and Groups I to VIII metals selected from Cs, Li, Rb, Mg, Th, Ca, Sr, Ba, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, La, Ce, rare earth metals, Hf, Ta, W, Re, Os, Ir, Pt, Au, Sn, Cd, Bi and Sb; and (c) a surface layer over said coating of 0 to 15% by weight of a metal or metal oxide selected from Cs, Li, Rb, Mg, Ca, Sr, Ba, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Y, Zr, Nb, Mo, Tc, Ru, Th, Rh, Pd, Ag, La, Ce, rare earth metals, Hf, Ta, W, Re, Os, Ir, Pt, Au, Sn, Cd, Bi and Sb; said powder composition having a specific surface area of 30 to 750 m2/g, a bulk density of 0.5 g/cc or more and a uniform pore diameter between the spheroidal particles in the range of 20 to 150 A said uniformity being such that 90% of the pore volume is of pores of from 0.6D to 1.4D in size, preferably 0.7D to 1.3D, where D is the median pore diameter.
The porous aggregates of this invention may range in size from 2 to 500 microns.
The aluminosilicates of this invention are pre-pared by a process comprising:
(a) preparing a heel scl of discrete colloidal particles selected Erom sodium, potassium or ammonium aluminosilicate, silica and one or more refractory me-tal oxices selected from the group consisting of titania, alumina, zirconia, thoria, lanthana and other rare earth metal oxides, said heel sol comprising particles of a substantially uniform diameter within the range of 2 to about 87 nano-meters, the initial concentration in the heel sol of sodium, potassium, ammonium aluminosilicate or total refractory metal oxide being at least 0.2% by weight with the particles stabilized against aggregation in the pH range 9 to 12;
(b) adding to said heel, separately but simul-taneously, two feed solutions, one being a solution of sodium or potassium silicate having from 1 to 36 grams of silica per 100 cc, or a sol of silicic acid containing from 1 to 12% silica, the other being a solution of sodium or potassium aluminate containing from 1 to 15% alumina, said feed solutions being added in relative rates and proportions to maintain a constant molar ratio of Si:Al in the feed streams of from 1:1 to 19:1 with the rate of addition of silica not ~o exceed 10 ~rams of SiO2 per 1000 square meters of total surface area of particles in the heel sol per hour;
(c) maintaining the pH of the heel sol at a constant value between 9 and 12 by adding a cation exchange resin in the hydrogen form until the particles in the heel sol have attained an increase in diameter of at least 1 nanometer and a maximum size of 90 nanometers;
(d) filtering the sol from (c) to remove the cation exchange resin and adjusting the concentration of the resulting aluminosilicate sol to a solids content of 1 to 60% by weight; and 3~3 (e) drying the resulting substantially gel-free sol of particles having an aluminosilicate surface to a powder by removing water at a rate at which no gelling will occur.
The sol from (d) may be ion exchanged to remove the sodium or potassium ions by contacting it with a strong acid type of cation exchange resin in the ammonium form, after whichthe solids concentration may be ad~usted to the range of 10 to 6Q~ by weight before drying the substantially gel-free aluminosilicate sol to a powder by removing the water at a rate at which no gelling will occur.
It will be understood that even when the heel sol is a refractory oxide or silica or aluminosilicate, the particles in the final sol product will have a coating of aluminosilicate and are referred to herein as an alumino-silicate sol.
The powders of this invention have substantially uniform pore sizes because the particles in the alumino-silicate sol before drying are substantially uniform in diameter. The uniform particle size of the sol results because the two individual species, the aluminate ions and silica or silicate ions, are not allowed to react to form new particles or precipitate. The aluminate ions and silica or silicate ions are converted to soluble forms of alumina and silica or silicate which are deposited on the substantially uniform sized nuclei or initial particles in the heel. When the alkaline solutions of silicate and aluminate are added, the pH of the mixture, but for the addi-tion of ion exchange resin,would rise. ~he addition of ion exchange resin is regulated to maintain the pH constant in the range of 9 to 1~.

3~:~3 The powders of this invention have an average pore size which depends on the average particle size of the precursor aluminosilicate aquasol. The aquasol is in turn obtained by deposition of sodium or potassium alumino-silicate on colloidal nuclei particles in the heel sol.
For these reasons the selection of the heel sol has to be made on the basis of what properties are required in the final powder and on the amount of aluminosilicate that is - - to be deposited.
In the process of the present invention what is meant by constant pH is maintaining the pH within ~ 0.2.
The addition of a cation exchange resin in the hydrogen form removes sodium ions and prevents the accumulation of sodium salt in the reaction medium that would cause coagulation of the colloidal particles.
Once the required spheroidal particles have been formed containing cations of sodium or potassium, there are the following ways in which the final powder o the in-vention can be made, depending on what cations are desired in the final product:
(a) The sodium or potassium ions in the sol may be ion exchanged, e.g., by hydrogen or ammonium ions and then the sol converted to powder by removing water.
(b) One or more cations of metals described herein to enhance catalytic activity may be added in limited amounts to the sol to partially replace hydrogen or ammonium ions before forming the powder.
(c) The sol containing the original sodium or potassium ions may be converted to powder and then the sodium or potassium ion exchanged for ammonium or one or -L~

more of the metal cations described herein. In this in-stance, removal of all sodium or potassium from the powder is substantially attained only where the pores oE the pow-der are large and only the outer surface of the spheroidal particles consists of aluminosilicate.
(d) In carrying out alternative (b) and (c), more cation metal may be used than required for ion exchange if it is desired to leave a thin film of metal on the alumino-silicate surface. Said metal deposited on the aluminosilicate is converted to hydroxide and oxide when the aluminosilicate is dried and calcined.
The metal cations of Groups I to VIII of the Periodic Table referred to herein include Group 1~ except for Fr, Group lB, Group 2A, Group 2B, except for Hg, Group 3B, except actinium, Group 4B, Group 5B, Group 6B, Group 7B, Group 8 and Sn, Sb and Bi.
The aluminosilicate powders of the present in-vention are made by drying sols of spherical discrete colloidal uniform sized particles to obtain dried aggre-gates of said particles in which the spheroidal particlesare closely packed together. The narrow pore size distri-bution of the powder of this invention is attainable with porous aggregates ranging in size from 2 to 500 microns, preferably 10 to 200 microns, although considerably larger powder grains can be obtained, depending on the method of drying. The uniform individual particles that compactly agglomerate to form the powders of this invention are selected from the range from 3 to 90 nanometers in diameter, depending on the desired resulting pore size. Larger particles result in a powder with uniform pores of a laxger size.

It is most important that loose aggregation o the particles or foxmation of gel networks of linked particles does not occur before water is removed. Otherwise, par-ticles become linked together in open three-dimensional networks in the sol, which may become viscous or even gel.
These open networks do not completely collapse upon removal of water and drying, thus leaving some pores appreciably wider than those remaining when the spheroidal particles are closely packed together upon being dried.
Most simply stated, drying should occur before aggregation or gelling occurs in the sol. One way to obtain a mass of close-packed colloidal particles is to force the water under pressure out of a sol through microporous membrane against which the silica particles become packed, and then drying the water from the wet solid filtercake.
However, the most convenient way is to concentrate the sol as much as possible, such as to a solids content of 10 to 60% by weight, without aggregating the particles and then to dry suddenly as by spray drying. In this case, the sol is concentrated rapidly in spheroidal droplets and the sur-face tension of the water compresses the mass of particles, forcing them together in spite of the mutualrepulsion due to the ionic charge on the surface, until they are randomly closely packed.
Figure l is an illustration of the dried particle structure of the aquasol of this invention in contrast to structures after gelation, coagulation or flocculation.
Figure 2 is a drawing of a spray dried porous aggregate of this invention.
Figure 3 is a cross section of a particle making up the aggregate where the particle is homogeneous and where there is a core o~ a refractory oxide.
Figure 4 illustrates the pore volume formed by the spheroidal particles of this invention.
Referring now to Figure 1, the gel structure formed after drying is shown after (a) gelation or (b) coagulation or flocculation of the aquasol of this in-vention. The dried structure of this invention with uniform pore size distribution is also shown after drying without gelation.
Referring now to Figure 2, the spray dried aggregates of particles of this invention is shown in a spheroidal shape to illustrate the uniform packing of the particles to form the aggregate. The individual particles making up the aggregate may be homogeneously an amorphous aluminosilicate or may have a core of silica, aluminosilicate or one or more refractory metal oxides with a coatin~ of said aluminosilicate as illustrated by Figure 3.
Figure 4 was merely included to illustrate the pore volume of this invention and its formation by the particles.
The theory of the shrinkage forces in drying water from wet masses or gels of colloidal silica has been described by R. K. Iler in "Colloid Chemistry of Silica and Silicates" (Cornell University Press) 1955, pages 140 to 143. The nature of the resulting gel or aggregate masses has been discussed by R. K. Iler in a monograph on "Colloidal Silica" in Surface and Colloid Science, Vol. 6, edited by E. Matijevic (John Wiley & Sons, Inc.) 1973, pages 65 to 70. The principles relating to colloidal silica also apply to $he present sols which are converted to powders.

~:~;23~

The colloidal particles which bear the highest ionic charge and which exert the greatest mutual repulsion in the end, form the most closely packed aggregates. The reason is that as the sol becomes concentrated the particles still repel each other and do not join together even when they are muchcloser to each other than their own diameter.
Thus, the uniform spheroids remain uniformly distributed as further water is removed, until the concentration raaches the point where all the particles are forced into contact at about the same time so that the spaces or pores between them are uniform in size.
If, however, the particles in the sol begin to form open three-dimensional aggregates, or "gel phase" as described by Iler in "Colloidal Silica", page 45, then these particles are no longer free to move together uniformly as the sol becomes very concentrated and when dried such particles are not fully closely packed and lar~er irregular pores then remain in the powder.
Since aggregation of the particles in a sol to form a gel is not an instantaneous process but generally occurs over a period of hours or days, the sol of this in-vention must be dried as rapidly as possible or before gelling at as low a temperature as consistent with rapid drying. Generally speaking, the sols suitable for drying do not gel in less than about an hour so that drying within one hour is desirable.
Spray drying is a preferred procedure not only because drying is rapid, but because the powder product is obtained as porous spheres typically 5 to 200 microns in diameter which are especially useful as catalysts.

f~3 ! ~, The surface of the ~owder consists of an alumino-silicate at least -to the depth of about 0.5 nanome-ter of -the formula indica-tecl above or it may contain a surface layer o~
the metal cations described in the following paragraph and amounting to 0 to 15% by weight of the core and alumino-silicate coating.
In the general formula, the hydrogen or ammonium ions may be wholly or in part substituted by cesium, rubidium, lithium or metal cations selected from the group magnesium, calcium, strontium, barium, scandium, titanium, vanadium, chromium, manganese, iron, nickel, cobalt, copper, yttrium, zirconium, niobium, molybdenum, technetium, ruthenium, rhodium, palladium, silver, lanthanum and elements of the rare earth lanthanide series numbers 58 to 71 in the periodic system, thorium, uranium, hafnium, tantalum, tungsten, rhe-nium, osmium, iridium, platinum, gold, bismuth, cadmium, tin and antimony.
The core of the spheroidal particles consists of the pre-formed colloidal particles on which the alumino-silicate is deposited. The chemical nature of the interiorof the particles plays no direct role in catalysis, since the particles are nonporous to organic molecules. However, the pre-formed particles must be thermally stable and pro-vide a suitable physical substrate for the aluminosilicate on the surface. Thus, the core may consist of aluminosili-cate, of any ratio of Si:Al from 1:1 to 99:1, and preferably 1:1 to 19:1, silica or one or more refractory oxides having a melting point over 1600C, which can be pre-formed as an aqueous sol of relatively uniform, more or less spheroidal colloical particles from 2 to 87 nanometers in diameter.
Typical refractory oxides are alumina, zirconia, titania, 1~3~

lanthana, thoria and rare earth oxides. However, such pre-formed particles must be oE such uniform size that after the aluminosilicate has been deposited, the final particles will meet the above requirement of uniformity. It will be noted that even if the pre-formed colloidal particles are cubic crystals of a refractory oxide, the shape becomes more rounded as amorphous aluminosilicate is deposited as an increasingly thick coating. If the pre-formed particles are the same as the aluminosilicate being deposited, then the particles are homogeneous and are ~imply grown in size.
The core material is supplied in the form of an aquasol, the preparation of which is known in the art. The size of the particles in the aquasol comprising the heel or core of the particles making up the powders of this in-vention can vary rather widely in view of the particle size range of ~ to 87 nanometers. The powder of this invention with large pores, would have, for example, large colloidal particles of 50 nanometers in diameter. These large particles may have an aluminosilicate surface or coating as little as 0.5 nanometer in thickness. Thus 83% of the volume of such particles may consist of a core material which may be a refractory oxide such as silica or alumina.
Thus in this case, aluminosilicate comprises only a minor part of the weight of the powder. On the other hand, the ultimate colloidal spheroidal particles making up the powder grains may consist throughout of aluminosilicate.
The powders of this invention with cores of a very stable refractory are more resistant to sintering than when they consist entirely of aluminosilicate. Thus, when the cores of spheroidal particles of this invention comprise more than 50~ of the volume of refractory par-ticles, the powders of this invention are more resistant to sintering which would close the pores thereof. The aluminosilicate surface may sinter and flow to some extent, but the thermally stable cores prevent collapse of the structure and closing of the pores. Thus, high surface area can be retained and by suitable partial rehydration of the aluminosilicate surface catalytic activity can be restored.
The colloidal particles in the heel or starting sol which constitute the core on which aluminosilicate is to be deposited must meet a number of requirements:
(a) The particles must be of generally spheroidal or equidimensional in width, thickness and breadth, with an average diameter of 2 to about 87 nanometers. Thus in making aluminosilicate-coated particles 3 nanometers in diameter, if the thickness of the aluminosilicate coating is 0.5 nanometer and the diameter of the heel sol particle is 2 nanometers, the final diameter will be 3 nanometers.
If it is 1.5 nanometers in thickness and the heel particles are 87 nanometers in diameter, the final particles will be 90 nanometers in diameter. As will be explained, the thickness of the deposited aluminosilicate should be greater when the particles of the heel sol are of a different com-position from the coating.
(b) The heel sol particles must be physically and chemically stable at high temperature. The refractory metal particles of the heel are characterized as having a melting point in excess of 1600C.
(c) The heel sol particles must be of a substance that can be made in the form of an aqueous sol of colloidal particles of uni~orm size.
The heel sol particles constituting the core of the particles making up the powders of this invention are selected from silica, a sodium or potassium aluminosilicate having a Si:Al molar ratio of from 1:1 to 99:1, preferably 1:1 to 19:1 and one or more rerractory metal oxides selected from the group consisting of alumina, zirconia, titania, thoria and rare earth oxides. The preferred refractory metal oxide is selected from alumina, zirconia and titania.
- The preferred heel particles are selected from silica, sodium or potassium aluminosilicate having a Si:Al molar ratio of ,from 1:1 to 19:1, alumina, zirconia and titania.
The preparation of such heel sol particles in the form of an aqueous sol is known in the art. Colloidal silica of uniform size has been described by R. K. Iler in "Colloidal Silica", in Surface and Colloid Science, Volume 6, E. Matijevic Editor (~ohn Wiley & Sons, Inc.) 1973, page 1. U.S. Patent 3,370,017 discloses the prepara-tion of aluminasols of many types. U.S. Patent 2,974,108 discloses aluminosilicate sols. U.S. Patents3,111,681 and 2,984,628 disclose zirconia sols. U.S. Patent 3,024,199 discloses sols of the rare earth oxides. Most refractory oxides can be made in the form of a stable aqueous sol except those such as calcium oxide, barium oxide or magnesium oxide, which tend to hydrate or dissolve to an undesirable extent in water. It should be understood that colloidal hydrous oxides, in which the oxide in the colloidal particle is chemically hydrated with some bound water that cannot be removed by vacuum at ordinary tempera-ture, is satisfactory for the present purpose, unless the loss of water at elevated temperatllre results in a ~ross ~hrinkage of the core within the aluminosilicate par-ticle.
Even if the small heel particles initially have a cubic or other approximately equidimensional shape, they become rounded when enough aluminosilicate coating has been deposited to form the spheroidal shape of the final sol particles.
If the available refractory oxide sol is not of sufficient uniform particle size, a fraction o~ suitable uniformity must be isolated by means known to those skilled in the art of colloid chemistry, such as fractional sedi-mentation or centrifugation.
The refractory oxide sols must be so constituted that the particles remain nonaggregated in a pH range wider than that at which the aluminosilicate is deposited, namely 8 to 12. Many refractory oxides including alumina, zirconia and thoria are stable by virtue of a positive charge on the particles wiih nitrate or chloride counter-ions at a pH below 5 or 6. Ordinarily, when the pH of such a sol is raised to 7 or 8 or higher, the particles coagu-late or gel.
To stabilize such sols at pH above 7, those skilled in the art are familiar with techniques for re-versing the charge on the particles by adding an excess of multivalent ions that are strongly adsorbed on the oxide particles at low pH and put a negative charge on the particles. Then the pH can be raised to the alkaline side with ammonia or sodium hydroxide. Citric or tartaric acid is often used for this purpose. Enough of said acid is added, to the oxide sol which is below pH 6, to furnish ~ 20 -~.23~3 one or two acid molecules per square nanometer of colloid o~ide surface, before the pH is used to the desired range.
In some instances, the charge of a positive oxide sol can be reversed by adding it in a thin stream at a point of in-tense agitation in a solution of sodium polymetaphosphate or sodium silicate. When the aluminosilicate deposition of this invention begins,it can displace the organic cations from the oxide particles, but generally not polymetàphos-phate, which remains in the product. For this reason, the phosphate is less preferred.
Where very small particles are required in the heel, e.g., an aluminosilicate sol of particles less than 5 or 10 nanometers in diameter, iL iS preferable to pre-pare the particles as a heel just before the aluminosili-cate is deposited. Where very small silica particles are wanted as nuclei, sodium silicate is added to water to obtain a silica concentration of 0.5 to 1.0% and the pH
is adjusted to 8 to 10.5 with ion exchange resin at a temperature of 30 to 50C. Initially, colloidal particles as small as 1 nanometer are formed and these grow in si~e spontaneously while diminishing in numbers, When the desired size is reached, the temperature is raised to at least 50C and deposition of the aluminosilicate according to the process of the invention is begun.
Similarly~ small particles of sodium aluminosili-cate can be attained in the heel by adding to water sodium silicate and sodium aluminate solutions to achieve the de-sired ratio of Si:Al and the combined concentration of SiO2 plus A12O3 of 0.2 to 0.5%. The pH is adjusted to 8 to 12, and the solution warmed to 50C before the deposition of aluminosilicate according to the process of the in-vention is begun.
Initially in such heel solutions, polymerization of the oxide occurs with initial equilibrium formation of clusters containing various numbers of molecules. Clusters that are smaller than a certain critical size have a ten-dency to redissolve, while clusters that are larger than this critical size will have a tendency to grow. Such critical size clusters of molecules are referred to in the art and herein as nuclei. In general, the term nuclei im-plies clusters of molecules or very small colloidal particles which are not in equilibrium with the dispersing medium and have a strong tendency to grow into larger particles.
Thus to make the smallest aluminosilicate particles the heel in the process of the invention can consist of water dispersions of nuc~ei of silica or aluminosilicate, said nuclei being freshly formed clusters of small particles having a tendency to grow and form larger particles. For somewhat larger particles, the heel can consist of a water dispersion of silica or aluminosilicate particles rather than nuclei, in equilibrium with the water.
For very small nuclei of refractory oxide around 2 nanometers in diameter, certain basic salts may be used providing they are suitably converted to stable negatively charged particles. Thus, basic aluminum chloride having the empirical for~ula A12(OH)5~1 actually consists o hydrated alumina units containing about 13 aluminum atoms bearing positive charges, surrounded by chloride ions in solution, as disclosed by Georg Johansson, Acta Chemica Scandinavica, Volume 14, page 771, 1960. By adding a dilute 3~

solution of the basic aluminum chloride, containing, ~or example, 0.3~ by weight of equivalent A12O3, to a very strongly agitated solution of ammonium citra~e so as to have present at least one citrate ion per chloride ion, a negatively charged complex is obtained. To this a dilute sodium silicate solution can then be added in an amount such that there are several silicate ions present per alumi-num atom. When the sodium is removed by exchange with a cation exchange resin in ammonium form and the solution heated to 50C, there is obtained a sol of silica coated alumina nuclei on which aluminosilicate may then be de-posited by the process of this invention until a particle size of 3 or 4 nanometers has been attained suitable for making a powder having very fine uniform pores.
Commercially available aquasols with particle diameters from about ~ to 60 nanometers may be used as a heel in the process of the present invention. Silica aquasols are used as nuclei where the silica composition of the core is not deleterious to the properties, most notably the thermal stability and the catalytic activity, of the final product.
As a general statement about forming very small particles of refractory oxides by hydrolysis of salts, the process o~ nucleation is influenced by several factors, especially those that affect the solubility of the nuclei.
The rate of formation of nuclei of a solid in watPr depends on the degree of supersaturation. The less soluble the substance formed, the higher will be the supersaturation, and thus there will be present more and smaller nuclei.
Sirce solubility in ~ater increases with temperature, the supersaturation level decreases with increasing temperature.
Thus, the lower the temperature, the more nuclei present and the smaller the nuclei for a given heel and the highex the temperature the fewer nuclei and the larger the nuclei for a given heel.
Generally, the range of temperature at which sil~
ica nuclei are formed by deionization of sodium silicate is 30 to 100C. In this case silica nuclei of about 1 to 6 nanometers in diameter are obtained. In the case of aluminosilicate sols the nuclei are formed at temperatures between 30 and about 50C. At higher temperatures there may be some formation of coarse precipitates instead of discrete particles. However,`although it is necessary in the case of the aluminosilicate to effect the deionization of the added soluble silicate and soluble aluminate at a relatively low temperature to obtain very small but discrete aluminosilicate nuclei, once a suficiently large number of nuclei of said aluminosilicate have been formed, the temperature can be increased to as much as 1~0C to accel-erate the build-up or growth o the particles.
The desired final particle size of the sol is dependent on the initial particle size nuclei of the heel and the amount of aluminosilicate to be deposited. When the final powder pore size desired requires small final particles of aluminosilicate r the initial heel should con-tain smaller particles. When small particles are used in the initial heel and the reactants build-up the nuclei to a larger particle, the core that constitutes the original nuclei has a negligible effect on the catalytically active surface of the final particles or powder. Thus, where the - 24 ~

nuclei are silica and the buil~-up or deposit constitutes a substantial part of the inal particle, the product ls essen-tially a homogeneous aluminosilica-te particle. In such cases the vol~e of original silica of the nuclei is negli-gible compared to the volume of the final particle and this small amount of silica has very little effect on the pro-perties of the final aluminosilicate solution.
When the nuclei are larger, relatively smaller amounts of aluminosilicate may be built up around the nuc~ei, depending on the finally desired particle size and pore diameter. When these larger nuclei are alumina, some overall physical properties of the final product will be somewhat different from those where the particles are homogeneous aluminosilicate, for example, density, refractive index and thermal properties. However, the surface pro-perties will be the same.
Particle size and concentration of the nuclei in the heel have an effect on the desired or practical build-up ratio. Build-up ratio ~BR) is the ratio between the total weight of solids in the product sol and the total weight of the nuclei in the heel, assuming all the added alumina and silica has been deposited upon the nuclei.
It is possible ~o calculate the build-up ratio on the basis of relative volumes, assuming densities for the heel nuclei and the deposited aluminosilicate. When the ratio is calculated as total volume of solids in the final sol particles divided by the total volume of solids in the heel sol, it is possible to calculate the average particle diameter in the final sol from the build-up ratio and the particle size of the heel sol.

-3~

As an example of build-up ratio by weight, if we start with a one-liter heel with a concentration of 1 g/100 ml of aluminosilicate (-total mass of nuclei 10 g) and during the process we add a total of one liter of sodium silicate solution with a concentration of 20 g SiO2/100 ml and one liter of sodium/aluminate solution with a concentration of 5 g NaAlO2/100 ml (total mass o SiO2 NaAlO2 250 g), the result is about 3 liters of a sol containing 260 g of solids. The build-up ration in this case will be 260/10, or 26.
Assuming that all the silica and aluminate accrete or are deposited uniformly on the aluminosilicate nuclei, there will be a relationship between the buila-up ratio MF/Mi (where MF is thè mass of solids in the final product and Mi is the mass of particles or nuclei initially) and the cube of the ratio between the particle diameter of the product DF and the nuclei diameter Di:

Mi ( D 1 ) When the layers of new material ormed on the nuclei are not porous to liquid nitrogen, the relationship between build-up ratio and specific surface area of the product (SF) and the nuclei (Si) as measured by nitrogen adsorption, will be MF ( Si )3 Mi ~F
However, it is pointed out that these formulae apply only when the density of the deposited aluminosilicate is the same as that of the nuclei particles. Where the densities are different, suitable corrections must be made.

~L2~ 3 Thus having selected the particle size or specific surface area of the final aluminosilicate sol, the formulae relating build-up ratio to particle sizes or surface areas and total masses or concentrations can be used to select the particle size and concentration of the required heel.
The nuclei or particles in the heel are caused to grow into a uniform particle size by the simultaneous but separate addition of a silica sol or a sodium or potassium silicate and sodium or potassium aluminate into a heel in the presence of a cationic exchange resin in the hydrogen form for pH control. The nuclei or particles in the heel grow by an accretion process. The cationic exchange resin in the hydrogen form may be added to the heel prior to the simultaneous but separate addition of the silica sol or the silicate and aluminate solutions, or it may be added at the time the addition starts or shortly thereafter.
Thereafter said resin is added to maintain a constant pH
+ 0.2.
It is required that the rate of addition of silica or silicate and aluminate is not permitted to reach that point where the silicate and aluminate will react in solu-tion and form new particles or a precipitate. The aluminate and silicate must be hydrolyzed and deposited as completely as possible on the nuclei. The build-up or growth of the nuclei in the heel is thus limited by the rate that will permit the molecules of silicate and aluminate to deposit on said nuclei. Generally, the silicate and aluminate must not be added at a rate greater than that by which 10 g of SiO2 per 1000 square meters of surface area is added to the system per hour. Generally, the addition of reactants -~lZ ;3~L3 will be such that 5 to 10 g of SiO2 are added per 1000 square meters of surface area available in the system per hour. Rates of addition above the maximum specified above are undesirable because they will permit new nuclei to form which will result in nonuniform particle size in the final sol.
The procedure of the present invention involves adding the solutions supplying the silica and alumina simul-taneously, but separately to the heel sol in which the particles are growing. Premixing the reactants results in the formation of a precipitate and therefore must be avoided. The heel is vigorously stirred during the deposi-tion process to permit almost constant dispersion of the reactant solutions. The use of very thin feed tubes or jets for the introduction of reactants assists in the dispersion of the reactants. Generally, the dischar~e of the feed tubes is inside the liquid of the heel immediately above the agitation blades. The heel sol may be circulated from a reaction vessel throu~h a centrifugal pump, thro~lgh a mass of weak base ion exchan~e resin in ammonium form, and then back to the vessel while the feed solution is fed in at a point close to the pump impeller.
The pH of the heel must be controlled to remove the sodium or potassium of the reactants and control the solubility of the particles. The pH is held constant within + 0.2 units, preferably + 0.1 at a value between 9 and 12, preferably 10 to 10.5. The addition of the reactants at a lower pH such as 8 would result in the formation of additional nuclei, and less complete deposition of the aluminosilicate on the nuclei. This is because the maximum rate at which deposition can occur is lower at lower pH.

3B~3 Generally, the temperature during particle growth is from 50 to 100C. Par~icle grow~h below 50C may be achieved but relatively slowly. The higher the temperature, the faster the rate of growth, but in any case, the speci-fied rate of addition of reactants should not be exceeded.
Temperatures above 100C may also be used provided care is taken to avoid evaporation by using greater than atmos-pheric pressure. However, at sufficiently high temperature under pressure certain compositions of aluminosilicate, particularly sodium aluminosilicate with a Si:Al ratio of around 1:1, tends to crystallize and the desired amorphous layer on the nuclei is not deposited. Instead crystalline nuclei tend to form in suspension. The formation of such crystalline zeolite compositions should be avoided. On the other hand, aluminosilicate compositions with Si:A1 ratios of 10:1 or 19:1 are less likely to crystallize and temperatures of up to 150C might be used if an economic advantage resulted.
The feed solution of sodium or potassium silicate may contain from 1 to 36~ by weight of silica, prefexably 15 to 25~ silica. The most preferred concentration is 20%
silica. Generally a feed solution of sodium silicate with a ratio of SiO2:Na2O of from 2.6 to 3.~ is preferred, while about 3.3 is most preferred.
The sodium or potassium aluminate solutions used in this invention may be purchased commercially, or they may be prepared from commercially available solid sodium or potassium aluminate. In preparing a solution of the aluminate, it is sometimes desirable to add excess alkali, e.g., NaOH or KOH or ~iOH, in order to decrease the extent `3~3~3 of hydrolysis of the aluminate, but -the amount should be minimized so as to reduce the amount oE ion exchange resin tha-t is needed.
Freshly prepared or commercially stabilized solu-tions free from precipitate should be used in any case.
The aluminosilicate surface that results from the accretion of the sodium or potassium silicate and sodium or potassium aluminate onto the nuclei must have a Si:A1 mole ratio of from 1:1 to 19:1. The concentrations and volumes of the added silicate and aluminate solutions must be such that they are within the above final ratio. This often places a restriction on the concentrations that can be used.
The aluminate solution may be as concentrated as 15% by weight aluminate, but at that concentration the addition would have to be very slow to prevent local precipitation of aluminosilicate. Generally, a solution containing aluminate is very convenient.
In the process of this invention the desired con-centrations of silicate and of aluminate being added must be held constant, unless compensating changes in the flowrate are made. Once the ratio of Si:Al desired is deter-mined~ and the rate of silicate addition is selected, the corresponding aluminate solution feed is set. The maximum addition rate of 10 g of SiO2 per 1000 square meters of surface area of the solids in the mixture per hour will thus limit the feed rate of both reactants.
Soluble electrolytes, such as sodium chloride, lithium carbonate or potassium nitrate, tend to coagulate the aluminosilicate particles. For this reason the heel and feed solutions should be essentially free of extraneous ~.23~3 elsctrolytes such a~ those indicat,ed~ Salts li~erating polyvalent cations should specifically be a~olded during ~he build-up operaton.
The build-up or growth is contlnued until the desired particle size i~ reached. At this point, the alumlnosilicate particles contain sodium or pota~sium cations.
The unifo~m particle size aquasols o~ this in-vant~on haYe ion-exchange propertie~. Although the partl-cles have ion-exchange proper~ies they are nonporous to organic molecules. Thi3 indicates that the Al in this com~osition is in the 4-~old coordination state a~ M A102 rather than ln the 6-~old coordination state as A1203. Each aluminum in the 4-~old coordination is accompanied b~ a Na or K ion. For this reason, the maximum total exchange capaclty can be calculated on the basls o~ the Sl/Al mole ratio.
me actual exchan~e capacit;~ ~or the v~rious metal ions that can replace Na or K in the alumino~ilicate aquasol can be measured by saturating the particles in the sol or powder with the speci~ic ion~ and e~ther analyz ~n~ the amount o~ metal in the solution a~ter separa~ing the aluminosilicate solids or by removing the excess o~
added s31~s and analyzing the solid phase ~or the speei~ie metal lon.
me aluminosilica~e sol m~ be treated with varlous ion exchange resins to remove the sodium vr potas-sium ions. In some case~ with aluMinosilicate o~ high Si:Al ratio the re~in in hydrogen ion for~ m~y be used, but the 30 ammonium ~orm is pr~ferred. Dowex* 5~TI-X83 an ion exchange ~denotes trade mark ,.

resin, is a strong acid cation exchange resin of sulfonated polystyrene-divinyl benzene type and is commercially avail-able from Dow Chemical Co. The sodium or potassium alumino-silicate solution is converted to the ammonium form by passing the solution through an ion exchange column packed with wet Dowex 50W-X8 previously converted to the ammonium form.
The aluminosilicate solution may be adjusted in concentration by dilution with water or concentration to the range of 5 to 40% by weight solids content before ion exchanging.
When the aquasols are converted from the sodium or potassium form to the ammonium form the sols are less stable. For example, an aquasol of 3.7 nanometers particle size with a concentration of 8 weight percent at pH 7 is stable in the Na+ form for at least 9 months at room temperature (R.T.) but the NH4 form of the same sol ~orms a gel after about one month.
It is important to notice that since the aquasols are only precursors to our powder compositions, it is not required that they are stable for longer than the period of elapsed time between sol preparation and drying.
In general, the sols of the present invention before drying are at least temporarily stable at a pH in the range from 4 to 12. The lower pH limit depends on the Si/Al ratio: the higher the Si/Al ratio, the lower the pH
limit of chemical stability for the sol. For example, a sol of Si/Al ratio of 1/1, when freshly made, is in equili- -~brium with 200 mg/l of Al expressed as AlO2 in the solution at pH 4 and R.T., but after 18 hours the AlO2 in the solu-tion increases to more than 300 mg/l. On the other hand, ~3~ l3 a sol of Si/A1 ratio of 6/l when Ereshly made is in equili-brium with lS m~l of A1 in the solution expressed as AlO2 at pH ~ and R.T. and the equilibrium is maintained Eor at least 18 hours.
The aluminosilica~e sols of this invention may be modified with various metals defined herein by replacing some of the ammonium ions with metallic ions. The metal de~ired in the final powder may be introduced by replacing the ammonium ion in the aluminosilicate sol by addition of a soluble salt of the metal. In this case a salt is selected with an anion such as nitrate or forma-te that can be elimin-ated by heating the powder at relativaly low temperature, or one that does not interfere with the use of the powdar as a catalyst.
The metal desired in the final powder can also be introduced in the aluminosilicate sol in some cases by re-placing the replaceable ammonium in the aluminosilicate sol using an ion exchange resin containing the desired metal ion prior to the drying step. The ion exchange step can be made by either the batch method or the column method.
Hydrogen can also be substituted for the replace-able ions by heating the ammonium aluminosilicate in the powder form to eliminate ammonia.
Some dilute sols with Si:Al ratios of lO:l or more having sodium or potassium ions may be exchanged directly with hydrogen ions, providing the particles are not allowed to aggregate before drying.
Metal cations that may replace the sodium, potassium or ammonium in the aluminosilicate solution be-fore drying may be Cs, Li, Rb, Mg, Ca, Sr, Ba, rare earth metals, transition metals, electron donor metals and Bi, Sn, Cd, and Sb.
What is meant by transition metals is Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Y, Zr, Nb, Mo, Tc, Rn, Rh, Pd, Hf, Ta, W, Re, os, Ir and Pt.
What is meant by rare earth metals is La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu.
What is meant by electron donor metals is Cu, Ag and Au.
The preferred cations to replace the sodium or potassium of the aluminosilicate are NH~, H, Ca, Mg, Mn, Ru, Rh, Pd, La, W, Re, Ir, Pt, Ce and mixed rare earth metals.
In all cases where metals are exchanged in the sol, conditions must be such as to avoid any aggregation or gelling of the sol particles.
Replaceable ions can also be replaced in the powder after drying by adding a metal soluble salt to a suspension of the powder in water and drying or separating the powder by filtration or centrifugation, washing and drying.
The final concentration of the aluminosilicate sol is limited by the final par-ticle size of the sol.
This is because the maximum concentration at which a sol is still stable with respect to gelation is a function of its particle size. Larger particle size sols can be concentrated to stable sols of higher concentrations than smaller particle size sols.
Table 1 illustrates the maximum stable concen-tration limits of aluminosilicate sol where the particles consist entirely of aluminosilicate:

Table 1 Particle Dia. ~ax. Conc. Alumino-(d) nanometer silicate, ~ by ~eight The maximum stable concentration, cm of lnter-mediate particle sizes appears to follow the equation c = 5,1d.56 m where d is the diameter of the particles.
The heel concentration likewise is limited by theparticle size of the sol but may vary generally from 0.
to 55% by weight of the aluminosilicate or silica. The uppper concentration level depends on the composition and particle diameter of the heel particles. Discrete silica particles are in general less solvated than aluminosilicate particles. Silica sols are stable toward gelation or flocculation at higher concentration than corresponding aluminosilicate sols of the same particle size. Thus, the upper limit o~ heel concentration is higher for silica than ~or aluminosilicate. However, as soon as deposition of aluminosilicate has started the sol of silica or other re-fractory oxide takes on the colloid characteristics of an aluminosilicate sol.
Low concentrations of heel sol are generally em~
ployed when the heel particles are very small or the build-up ratio is to be high. Concentrated heel sols are used only when the heel particles are large and only a low or moderate build-up ratio is anticipated. In any case, it is advan-tageous to start with as concentrated a heel sol as is practical so as to provide as much surface as possible or deposition of aluminosilicate and thus permit the coating process to operate at maximum allowable speed.
The particle size and particle size distribution of the colloidal particles of the aquasol can be determined by counting techniques involving micrographs obtained with the electron microscope by transmission or scanning electron micrography. The electron micrographs also show that the ultimate particles of the sol are essentially discrete or unaggregated.
The following table illustrates results of particle size distribution determinations of homogeneous aluminosili-cate aquasols of this invention obtained by ele~tron micro-graph counting techniques.

h Eo~ Q h~ N
z ~;2; ,~il ~ ~ ~ tD

a~

U U~

. ` I ,1 _I N ~) ~

r-l N ~ d' li~ ~D
O Q O O O O

- 37 ~

~3~3 The sols prepared by the process of this invention may contain 3 to 70~ solids dependincJ on their composition and particle size. The sols are stable, that is their vis-cosity does not increase substantially when stored at room temperature (20 to 35C~ over a ten~month period.
The amorphous aluminosilicate sols having uniform particle sizes, prepared by the process of this invention, are dried to achieve a powdered amorphous aluminosilicate with uniform pore size distribution. In order to attain the uniform pore size, the particles must pack themselves uniformly into a porous aggregate so that the final mass or aggregate is not bridged by particles leaving larger voids internally.
The sols of this invention consisting of uniform-sized particles have the characteristic that as water is removed and the percent solid increases, the viscosity does not change drastically until a certain rather narrow concen-tration range is reached, after which further increase in concentration causes a sharp increase in the viscosity of the sol. This particular concentration range depends to a large extent on the ultimate particle size of the sol~ If the sol is concentrated up to this more or less critical concentration, W, so that it becomes viscous, it becomes unstable in the sense that ihe viscosity of the sol will then spontaneously increase with time even though no more water is removed. If this spontaneous increase in viscosity is permitted to occur, the sol is converted to a solid mass of hydrated gel containing all the water that was present in the sol. When a gel of this type is then broken up and further dried to a powder, it is found that the pore dia-meter in the dried gel is not uniform.

On the other hand, if the sol is rapidly and con-tinuously concentrated beyond W by further rapid removal of water, the viscosity increases until -the mass becomes riyid.
When this is further dried it is found -the pores are uniform.
Thus, if the sol has been concentrated to some point less than W, and then it is dried very rapidly as by spray drying, the water is removed and the ultimate particles move closely together to form a closely packed mass~ In such a powder the pores between the particles are relatively uniform. In order for this to occur the water must be re-moved relatively quickly so that the particles do not have time to form the chain networks that occur during the gelling process.
Accordingly, drying must be sufficiently rapid that once the critical total solids concentration W is reached, water is removed fast enough to prevent bridging of the sol particles and consequently gelling. ~n example of too slow water removal is where the sol was allowed to stand at elevated temperature in a humid atmosphere. How-ever, it is usually most economical to dry using processeswhere the sol is fed in drops or thin streams of liquid or "atomized" in a fine mist so that water is removed from the sol particles in a matter of seconds. If, however, freeze drying techniques are used, the sublimation or water re-moval can be extremely slow but still no gelling will occur.
However, other forms of drying will result in gelling if sufficiently slow.
Once the sol has ~een prepared, it may be neces-sary to further concentrate it in order to minimize the amount of water that must be removed when it is dried from 3~ 3 the sol to a gel powder. In some instances, this concen-tration may be so high that the sol is only temporarily stable, as evidenced by the fact that the viscosity in-creases with age due to the incipient formation of gel.
It is important that if the sol has to be concen-trated to the point where experience shows that it is only temporarily stable, the sol should be dried at once before the viscosity has increased appreciably.
Examples of suitable drying processes include tray dryers, sheeting dryers, rotary dryers, spray dryers, through-circulation dryers, cylinder dryers, drum dryers, screw conveyor dryers, agitated pan dryers, freeze dryers, vacuum dryers, etc.
Adding alcohol or electrolytes to precipitate the aluminosilicate to separate by filtration or centrifugation the solid particles from the bulk of the water and drying the wet residue, will cause bridging of the particles, forming a precipitate, a coagulum or a gel with nonuniform pore size.
The preferred drying method is spray drying. Spray drying involves the "atomization" of the sol into a mist made of finedrops which dry almost instantaneously in con-tact with hot air. Spray drying produces a regular hollow, spheroidal, porous aggregate with a uniform pore size dis-tribution where the average pore diameter as measured by nitrogen adsorption-desorption techniques is roughly half the diameter of the particles forming the closely packed, porous aggregate. The average diameter of the aggregates and the aggregate size distribution can be controlled by controlling the conditions of spray drying. For example, B~L3 the type of atomizer used in spray drying influences the microspheroidal aggregate size distribution of the product.
Rotating discs produce more uniform a~greya-te size distri-bution than pressure noz~les. In the case of two-fluid pressure nozzles or pneumatic atomization, the lower the concentration of the aquasol fed into the spray dryer, the higher the atomizing force (feed pressure in the spraying nozzle), and feed rate, and the lower the inlet drying temperature, the smaller the aggregate size.

When the sol is drum dried the aggregates tend to be irregularly shaped and the product shows a vexy broad aggregate size distribution. However, within the aggre-gates, the original aluminosilicate particles are very closely packed, and since they are spherical, the pores that they create within the assembly have a very uniform size distribution and the average size is approximately half the diameter of the uniformly sized particles con-stituting the assembly.
The pore size distribution of powders of this invention is such that 90% of the pore volume is made of pores with pore diameters between 0.6D and 1.4D, preferably 0.7D to 1.3D, where D is the median pore diameter as esti-mated from the results of pore size measurement with the nitrogen desorption method described below. The experi-mental average pore diameter as defined below and as mea-sured by this method is between 20 and 150 A
To obtain such a close packing of particles and therefore such a uniform pore size distribution, the aquaso7 has to be dried wi-thout substantial gelling or coagulation.

When the particles are allowed to remain ~3~3 unaggregated until rnos-t of the water between the particles evaporates, the surface -tension o~ the water film around the particles, and especially in crevices around points of contact between particles, creates a force equivalent to compressing the assembly particles at high pressure. As a consequence, each sol droplet forms an aggregate or more of closely packed spherical particles. In this case, the pores are fairly regular in shape throughout the aggregate, and the size of the pores is very unifo~-m.
The composition of this invention can be charac-terized by their chemical analysis, X-ray analysis, speci-fic surface area measurement, pore size and pore size dis-tribution determination, appearance under the electron microscope by transmission electron microscopy (TEM) and scanning electron microscopy (SEM), aggregate size measure-ment with Coulter counter, surface acidity measurement by titration with adsorbed indicator in nonaqueous liquid phase, ion exchange capacity, infrared analysis, differential thermal analysis (DTA), thermogravimetric analysis (TGA) and measurement of bulk density.
The chemical composition of the powders of this invention can be determined by analytical techniques con-ventional in the art. Broadly, the powders comprise chemi-cally combined silicon, aluminum, hydrogen, oxygen and a metal ion, and physically or chemically combined water.
Water associated with the aluminosilicate can be analyzed by infrared, DTA and TGA techniques conventional in the art.
Water can be in the form of physically adsorbed ~0 H2O,chemisorbed H2O and OH structural groups. Chemisorbed -lL;~38~3 H2O includes water of hydration oE Na ions and H-bound water on the surface of -the partlcles. Physicall~ adsorbed H2O is released at atmospheric pressure at 100C and chemisorbed H2O between about 100~ and 200C. There is more than one kind of OH structural group. Most OH groups stay on the surface of the aluminosilicate particles only up to temperatures in the order of 600 to 700C.
Thermogravimetric analysis of sald compositions in the Na form shows a gradual weight loss up to about 800C
and very little weight loss at higher temperatures. The total weight loss of the spray dried powders is about 20~.
The structure of said compositions is shown to be amorphous by X-ray diffraction analysis.
Specific surface area of the powders of this in-vention can be measured by the well known BET method in-volving nitrogen adsorption [Brunauer, S.; Emmett, P. H.;
and Teller, E. J.; J. Am. Chem. Soc. 60, 309 (1938)] or by a nitrogen adsorption method involving continuous-flow equipment based on principles of gas phase chromatography [Nelson, F. M., and Eggertsen, F. T., Anal. Chem., 30, 1387 (1958)]. Results of surface area measurements and electron micrograph observation of the precursor sol and the resultant powder can be combined and show that the powders of this invention are constituted by closely packed dense spherical or spheroidal particles nonporous to nitrogen with a uniform particle diamPter in the range of 3 to 90 nanometers forming porous aggregates with an aggregate size larger than 1 micron.
Specific surface area of the powders of this in-vention range between 30 and 750 m2/g. Diameter of the nonporous spherical par-ticles making up the aggreyates can be calculated by the formula:
Particle Diameter Enanometer] =

Specific Surface Area [m /g] x Density of the Partlcles [g/cc]
The clensity of the particles can be measured by techniques well known in the art. The density varies with the chemical composition (Si/Al ratio) of the particles.
The shape and size of the aggregates are estimated from electron micrographs taken by TEM or SEM. For aggregates smaller than 100 ~m, it is convenient to use micrographs made by transmission electron microscopy or by scanning electron microscopy.
Micrographs of powders of this invention made by spray drying show hollow spheres ranging in diameter between 1 and 200 microns. The aggregate size and aggregate size distribution of these spheres is a function of the conditions used for spray drying and whether a rotary disk or a spraying nozzle is utilized. Aggregates obtained by drum drying are irregular in shape and have an irregular size in the micron range.
Aggregate size and aggregate size distribution can also be obtained by a well known technique using the Coulter counter ("Particle Size Measurement", T. Allen, 2nd Edition, Chapter 13, Chapman ~nd Hall, London, 197~). The Coulter technique is a method of determining the number and size of particles or aggregates by suspending the powder in an electrolyte and causing the particles or aggregates to pass through a small orifice on either side of which is immersed an electrode. The changes in resistance as particles pass l3 through the orifice generate voltage pulses whose amplitudes are proportional to the volumes of the par-ticles. ~he pulses are amplified, sized and counted and from the derived data the size distribution of the suspended phase may be determined.
Pore volume, average and median pore diameter and pore size distribution can be calculated using data on nitro-gen adsorption and desorption obtained on a Model 2100 D
Orr Surface-Area Pore-Volume Analyzer. This instrument is available from Micromeritics Instrument Corporation of Norcross, Georgia.
Pore volume distribution analysis can be made based on the method proposed by B. F. Roberts, J. Colloid and Interface Science 23, 266 (1967). This method provides a consistent method of pore volume distribution analysis allowing to estimate the distribution of the pore volume and area of a porous material as a function of pore size. The limitations are very few. The range of pore diameters is 20 A < pore diameter ~ 600 A. Other limitations are common to all procedures which use the capillary condensation approach including the fact that the pore model may not be representative of the pore structure.
Results are computed using a PORDIS-PORPTL com-puter program which generates BET surface area calculation, nitrogen desorption isotherm, plots of pore volume distri-bution, surface area distribution using the assumed pore model (cylinders) and plot of cumulative percent of both the pore volume distribution and surface area distribution.
Specific surface area is determined by the BET method.
Average experimental pore diameter is calculated by the ~ 45 -~2~ 3 ratio pore volu~e at saturation to the BET surface area.
A plot of the cumulative percent of the pore volume dis-tribution permits median pore and maximum and minimum dia-meter of pores constituting 90~ of the pore voluine to be determined.
The powders of this invention as measured by the method mentioned above showed median pore diameters between O O
20 A and 15~ A with 90~ of the pores in the approximate range _ 40% of the median pore size. The pores of the powders of this in~ention are of such uniforinity that 90~
of the pore volume lies in pores that are from 0.6D to l.~D
in diameter, where D is the median pore diameter.
The powders of this invention have a "tapped"
bulk density of at least 0.5 gram per cubic centimeter.
"Tapped" density is measured by placing a weighed quantity of sample in a graduated cylinder, and tapping the cylinder until the volume is essentially constant. If the bulk density is less than about 0.~ g/cc, it will be found that the powders are extremely difficult to compact uniformly, and will give catalyst pellets or compacts having internal strains and in which stratification of the solids will be present.
When the bulk density of the powder as dried is too low as it may be in the case of some drying techniques, the bulk density can be increased by pressing the powder at low pressures into a compact and breaking up the compact to screen it or to use it in the form of small granules or particles.
The amorphous aluminosilicate powders of this invention are effective catalysts. Their uniform pore ~:~23~

openings permit them to discriminate on the basis of size and configuration of molecules in a system. For example, the narrow pore size distribution of -the powders of this invention enable them to be more effective catalysts in petroleum refining and catalyst cracking processes by their improved selectivity. The narrow pore size distribution of the powder permits the selection of a pore size for the catalytic operations without the accompanying of widely varying selectivity based on wide pore size ranges. Thus, the powders of this invention give an optimum catalyst selectivity in cat cracking operations whereby the desired isomers are obtained through narrow control of the pore size.
The compositions of this invention are amorphous aluminosilicates. Crystalline aluminosilicate zeoli~es are known to possess among other properties catalytic activity.
However, crystalline aluminosilicate zeolites are so highly active as catalysts that, when used in the pure state, com-mercial catalytic crac]cing units cannot easily control the reaction involved to give desirable results. The present trend in the petroleum industry with regard to such zeolites favors the use of Y-type synthetic faujasite crystalline zeolites of silica~alumina ratios of 4.5 to 5.5/1 because they are thermally and hydrothermally more stable than X-type synthetic faujasite crystalline zeolites of silica/alumina ratios of 2.5/1.
The powders of this invention can be used together with crystalline aluminosilicate zeolites. The uniform distribution of crystalline zeolites within said powders as a matrix substantially improves the performance of the 3~

zeolites in catalytic cracking by diluting the active zeo-lite and moderating its activity while taking advàntage of the benefits of the powders of this inven-tion. The amor--phous aluminosilicates of this invention are specially suited for this purpose because (1) they provide a matrix cataly~
tically active itself (instead of inactive), (2) they pro-vide access of reactants to the zeolite crystals through pores of controlled size and controlled size distribution and therefore controlled selectivity, (3) they are stable to the high temperature hydrothermal treatment received in commercial regenerators, and (4) they form aggregates or grains hard enough to survive interparticle and reactor wall collisions without excessive breakage or attrition. However, the use of the amorphous aluminosilicates as a matrix and co-catalyst is not limited to one type of crystalline zeolite. The choice of crystalline zeolite to be incorpor-ated in the amorphous aluminosilicate of this invention is based on the type of reaction involved and the type of reactor unit available.
Another advantage of the amorphous aluminosilicates as matrices or co-catalysts with crystalline zeolites is that preferred ions, as for example the mixed rare earth ions in the case of catalytic cracking catalysts, can be uniformly and intimately distributed in the matrix by ion exchange techniques described herein for the parent amorphous alum-inosilicate aquasol or the powder obtained by drying the aquasol.
The crystalline aluminosilicate zeolites are well known in the art and described in detail, for example, in Donald W. Breck's book on "Zeolite Molecular Sieves", Wiley-Interscience, New York, 1974.

~2~3 Compositions involvin~ known crystalline alumino-silicate zeolites and the amorphous aluminosilicates of this invention can be made by using the mixing, compounding, etc., techniques disclosed in the art to make zeolite-amorphous aluminosilicate catalysts (see for example, "Preparation and Performance of Zeolite Cracking Catalysts", by J. J.
Magee and J. J. Blazek, Chapter 11 of ACS Monograph 171~
"Zeolite Chemistry and Catalysis", edited by J. A. Rabo, ACS, Wash. D.C. 1976) or by other techniques specially suited to the characteristic properties of our compositions. For example, one way of intimately and uniformly distributing crystalline aluminosilicate zeolite crystals in the amorphous aluminosilicate matrix is to disperse the zeolite crystals of microscopic size in the amorphous al~minosilicate aqua-sols of the present invention, followed by drying of the aqueous dispersion in the manner described herein.
The amount of crystalline aluminosilicate zeolite that is advantageously incorporated in the amorphous silicate powders of this invention generally is from 5 to 50% by weight. Thus, catalyst cracking compositions can consist of 5 to 50~ by weight ~preferably 10 to 25%) of crystalline aluminosilicate zeolites and 95 to 50% by weight (preferably 90 to 75%) of the amorphous aluminosilicates of this invention.
The following examples further illustrate the compositions of this invention and the methods for their preparation. In the examples that follow, all parts are by weight unless otherwise noted.

This is an example of the preparation of a hydrous ~ 2~3 amorphous alumlnosilicate powder of the invention where a heel of ~ilica ~ol is used to form the core Or the particle~
making up the powdersO
A heel solution was prepared ln a reactor vessel ~itted with stirrer paddles in the ~ollowing manner: 2000 ml of water were heated to 50C and 20 ml o~ sodium 3~
cate JM diluted to a con~ntration Or 20 g SiO2/100 ml were added. Sodium silicate JM i8 an aqueous solution oP sodium silicate with a Sio2/~a~O weight ratio of 3.25 and a con-centration Or 29.6 weight percent silica (41.9 g SiO2/100 ml)~Ten grams o~ cationic ion exchange resin, Amberlite* IRC-84-S, in the H+ Porm were then added and the pH of the solution dropped ~rom 10.2 to 9. At thls point a dilute sol (0.2 g SiO2/100 ml) o~ extremel~ small ~ilica particles is rormed. Amberlite IRC-84-S ls a weak-acid carboxylic methacrylate cation exchange resin available from Rohm & Haas Company of Philadelphia, Pa. mis resin has a total exchange capacity of 3.5 meg/ml wetJ an approximate pK value of 5.3 with respect to sodium in a 1 mola~ solu-tion, an apparent wet density Or 0.75 g/cc, an e~ectiveparticle ~ize of 0.38 to o.46 mm and a pH ran~e 4 to 14J
maximum operating temperature for this resin ls about 120C.
To this heel two feed solutlons were added slmul-taneously and separately with vigorous agi~ation o~ the heel. One solution was an aqueous solution o~ sodium sili-cate with a SiO2/Na20 weight ratio 3.25, with a silica concentration oP 20 g~100 ml and the other ~as an aqueous solution of sodium aluminate, ~ith a concentration oP
~A102 o~ 5 g/100 ml. The sodium alumina~e ~olution was prepared ~y dis~olving 67~61 g o~ Nalco* 680 grade ~odi~m aluminate in enou~h O.lN ~aO~ to ~ake 1 liter o~ ~olutionO

*denote~ trade mark '~3 l~X;3~

Nalco 680 is the Nalco Chemical Company, Chicago, Illinois, trademark for a white granular sodium aluminate trihydrate.
Maximum solubility of Nalco 680 at 22C is 80 parts in 100 parts of water. Nalco 680 has a Na2O/A12O3 mole~ular ratio of 1.12 to 1, A12O3 content is 46%, and Na2O content 31.0~.
This analysis corresponds to 73.95% NaAlO2. The sodium silicate solution was prepared by mixing 1351 g of JM grade sodium silicate with enough tap water to make 2 liters of solution. The two feed solutions were fed through capillary tubes into the heel solution just above the stirrer paddles at a rate of 4.3 ml/min for the silicate and 5.9 ml/min for the aluminate. Throughout the run the pH of the heel was kept constant at pH 9.1 + 0.2 units by periodically adding measured amounts of the IRC-84-S ion exchange resin and temperature was kept constant at 50C + 1C. Measurement of pH was done continuously at room temperature with a glass electrode by circulating part of the heel through a cooler.
A total of 1265 ml of sodium silicate solution, 1650 ml of sodium aluminate solution and 610 g of resin were used. At the end of the addition, the product was filtered first through cloth and then through filter paper to separate the resin from the aquasol. The pH of the product was 9Ø
The resulting product was 3~9 liters of a stable sodium aluminosilicate sol having a pH of 8.9. Solids concentration was determined by evaporating a weighed sample to dryness and calcining to eliminate H2O The solids concentration was 8.1 g per 100 ml. Chemical analysis of the resulting sol indicated that it contained ~:~23~3~L3 5.50 g SiO2/100 ml, 1.45 g AlO2/100 ml, and 0.47 g Na/100 ml.
Thus the resulting product was an aluminosilicate sol hav~
ing the approximate empirical formula of NaA102 3.75 SiO2-n -H2O. An electron micrograph of the sol showed very small particles in the order of 5 nanometers diameter or less.
To determine the degree of aggregation which is an indication of the closeness to gelling~ the percent hydrated colloid solids or percent S value was calculated from a measurement of viscosity in an Ostwald pipette and found to be 40. Calculation of percent S was made using the Mooney equation as described in ~. Colloid Sci. 6, 162 (1951).
The value of 40 indicates there is no extensive aggregation.
The sodium aluminosilicate sol was converted to the ammonium form by passing it through an ion exchange column packed with wet Dowex 50W-X8 ion exchange resin in the NH4+ form. Dowex 50W-X8 is the trademark o~ the Dow Chemical Co. for a strong-acid cation exchange resin of the sulfonated polystyrene-divinylbenzene polymer type.
Dowex 50W-X8 has a total exchange capacity of 1.7 meq/ml wet resin. Mesh size of the wet resin is 20 to 50, density is 50 to 53 lb/ft3 and moisture content as shipped by the manufacturer in the H form is 53%. Effective pX range of Dowex 50W-X8 is 0 to 14, and the resin is stable up to 150C. When the sol was thus treated, N~4~ ions replaced most of the Na ions attached to AlO2 sites and chemical analysis showed that only 0.017 g Na/100 ml (3% of the original Na content) remained in the aquasol.
The ammonium aluminosil~cate thus formed had a pH of 9 and it was spray dried in a Bowen Engineering, Inc.
No. 1 Ceramic Dryer using a two-fluid nozzle type 59-BS.

Operating conditions ~or spray drying were the following:
Feed Weight ~ solids:
Total feed: 2000 ml Feed rate: 120~125 ml/min Inlet temp.: 300~310C
Outlet temp.: 140-148C
Atomizing pressure: 20 psig Powder samples were collected in the cyclone and chamber collectors. Total product collected was 128 g for 80% recovery on a wet basis.
Electron micrographs of the spray dried powder showed that it was constituted by spheroidal aggregates with an average diameter of àbout 15 microns.
Chemical analysis of the powder gave the follow-ing Si/Al ratio and A12O3 content:
Si/Al ratio 3.75:1 A123 17~ by weight.
Surface area and pore volume, pore diameter and pore size distribution analysis of the spray dried powder were made by a nitrogen absorption-desorption method using a Micromeritics 2100-D apparatus. Micromeritics 2100-D
is the trademark of Micromeritics Instrument Corporation of Norcross, Georgia, for an Orr Surface-Area Pore-Volume Analy~er.
Results were obtained as follo~s:
Specific Surface Area 590 m /g Experimental average pore 22 A
diameter Pore volume 0.330 ml/g Pore volume distribution analysis was made based on the ~. F. Roberts method [J. Colloid and Interface ~3~

Science 23, 266 (1967)] and the results computed and plotted using the PORDIS-PORTL compu-ter program.
The arithmetic probability plot of the pore dia-meter versus pore volume data computed by the PORDIS program showed a median pore diame~er of 28 A. Ninety percent of ; the volume of the pores was constituted of pores ranging in diameter from the smallest measurable by the method (20 A) - up to 39.5 A (41% above the median pore diameter). Seventy percent of the volume of the pores was constituted of pores ranging in diameter from 20 A, the smallest measurable by the method, up to 32.5 A (16~ above the median pore diameter).

The usefulness of the product of this invention in cat cracking could be illustrated by this example.
Using the procedures well known in the art, 200 parts of the dried product obtained above is intimately mixed with 800 parts of an acid-activated halloysite clay, blending in sufficient water to produce a thin paste. The paste is prepared to the consistency required for extrusion and is converted by extrusion to l/8" x l/8" cylinders.
It should be noted that if a more abrasion resistant mater-ial is required, the product can be pilled on a typical pharmaceutical pilling machine to obtain harder and much stronger material than that obtained by extrusion.
After forming into the cylinders, the catalyst is impregnated with 0.5% Pd by ion exchange from an aqueous solution of palladium tetraamine chloride. The dried cata-lyst is then reduced and charged to a typical small scale hydrocracking test unit where the following conditions per-tained and results obtained.

- 5~ -3~3 3 Charge: Catalytically cracked gas oil Temperature 650F
Pressure, psig 1600 Liquid space velocity 2.50 H2/oil ratio scf/barrel 8000 Product: Jet Fuel Weight percent based on feed 65.2 Specific gravity 0.802 Sulfur content ppm 950.0 Freezing point -76F
H2 consumption scf/bbl 2050.0 This is an example of the preparation of a hydrous amorphous aluminosilicatepowder of the invention where a heel of silica sol prepared in situ is used in the apparatus described in Example 1 to form the core of the particles of this invention.
A 1~ silica sol heel was prepared in situ at 70C
and pH of 9 by diluting 160 ml of 20% SiO2 sodium silicate JM (SiO2/Na2O weight ratio 3.25) to a total volume of 3000 ml with hot tap water to make 3 liters of 1.06% SiO2 heel (32 g SiO2 in 3000 ml of solution). The heel was heated to 70C and then deionized to pH 9 + 0.1 with 80 g of ion exchange resin Amberlite IRC-84-S. A sample of the solution was extracted at this point to measure specific surface area of the silica thus formed. Specific surface area of the silica as measured by the titration method of G. W. Sears in Anal. Chem. 28, 1981 (1961) was 675 m2/g. Assuming that the silica is in the form of spherical particles of amor-phous SiO2 of density 2.2 g/cc the average particle diameter - ~5 -of the sillca calculated on the basis of the specific surface area value obtained is 4 nanometers. Feed solutions were added in the manner explained in Example 1 to build-up with sodium silicate and sodium aluminate, each at a rate of 12 ml/min while simultaneously heating the heel to 100C.
Heating from 70C to 100C took about 30 minutes. The two feed solutions of Example 1, aqueous sodium silicate solu-tion 20 g SiO2/100 ml and aqueous sodium aluminate solution 5 g NaAlQ2/100 ml were used. In 10 minutes the pH of the heel rose to 10.3 due to the alkalinity of the feed solu-tions being added. From this point on the heel was kept at 10.4 + 0.1 by periodic additions of IRC-84-S resin.
A total of 3958 ml of sodium silicate solution, 3950 ml of sodium aluminate solution and 1440 g of resin were used. At the end of the addition the hot colloidal solution obtained was filtered first through cloth and then through filter paper to separate the ion exchange resin from the aquasol.
The resulting product was 9n50 ml o a stable sodium aluminosilicate sol of pH 10.7 containing 10.72 g/100 ml solution. Solids concentration was determined as disclosed in Example 1. Chemical analysis of the resulting sol indi-cated that it contained 10.4 g SiO~/100 ml, 1.44 g AlO2/100 ml and 0.854 g Na/100 ml. Thus the resulting product was an aluminosilicate sol having the empirical formula NaAlO2~7SiO2 nH2O. The specific surface area of the sol was determined after the sol was dried by measuring the sur-face area by nitrogen adsorption using the flow method.
Specific surface area thus measured was 135 m2/g.

An ~l~ctron micro~raph o~ th~ sol 3howed dlscrete ~pheres Or unif~rm diameter. Weiaht a~rerage diam~er was 18 nanomoter~ and number average diameter W~8 16 nanom0ter3.
m~ standard devlation in both ca~o~ was 3 r~allom0ter~.
~ he ~ol wa~ conver~ed ~o the ammonlum rorm by ion ex~hang~ in th~ manner dascribed in Example 1.
~ he ammon~um alum~o~ cate thus rormed wa~ d ln vacuum ~n a Hoi~man drum dryer at 100C. A Bu~lo~rak*
laborato~r ~ize vacuum double drw~ yer ~anuracturod hy the Bu Malo Foundry & Machine Co. was w ed. It had t~o 18x18 Type 304 ~talnless steel dru~s, 6~ diameter x 8" ~ace~
designed ~or 150C steam ox 100C waterO The casin$ wa~
de~i~ned ~or rull ~acuum and pro~ided with door6 ~or access into the drum~ Drum ~pacing ~as adJu~tabl~ ~rom th~ out-side shell. The ~ol ~a~ allowed to dr~p into the cavi~y rormed by the two hot rotatin~ me~al cylind~r~ Tho cylin-ders ~ere under vacuum and heated inter~ally wlkh ~team at 100C, ~hererore a ~ery ra~t rate o~ Pvapora~ion ~a~
achieved. The dried ~at~rial was scraped with a 2YP~ 410 hardened chro~e steel cutt~ng knire. Dr~ condltion~ were as ~ollows:
St~am Temp3rature 100-103~C
Vacuum 8-15 mm Drum Spe~d 7 rpm m e drum dried powder was analyzed ~or ~pec~fic surPace area, pore ~olume, pore diameter and por~ size d1~tr~but~on as in Example 1. The reæults obtain~d ~ere a~
~ollo~:
Speei~ic surfa e area 250 m2~g Eæp~r~m~ntal avera~e O
pore diameter ~0 A
Pore ~olume 0~256 ml~g ~d~notes trade m~rk ~. .
. .

~ LZ3~3 The data showed a median pore diameter of ~3 A.
The upper (52.1 A) and lower (27.9 A) limits for 90% o the pore volume were within the median pore diameter~
Chemical analysis oE the powder showed that Si/A1 ratio was 3.75 and A12O3 content 18% by weight.

The usefulness of the product of the invention for Fluid Catalytic Cracking Operations (FCC) could be illustrated by the example.
Using the procedures well known in the art, 200 parts of the dried product obtained above is intimately mixed with 800 parts of an acid-activated halloysite clay, blending in sufficient water to pxoduce a thin paste. The paste is prepared to the consistency required for spray drying and then the spray drying operation is performed, and a microspheroidal product is obtained.
The catalyst thus obtained is evaluated in a typical bench scale fluid catalytic cracking converter equipped so that the catalyst can be treated beore test with steam at 1100F and 20 psig for 10 hours. Thereafter, the fluidized catalyst is treated with H2S for 2 hours also at 1100F but at only 10 psig.
A feed of Lybian gas oil of 650 to 1120F boiling range is processed at temperatures of 880 to 1020F to produce the following products at the low, mid-point and top of the reactor temperature ranges.

~r ~ U ~ ,1 ~D O ~ r~ ~ o o ~n ~ $ ~ ~
3: ~,~ '~ In u a~
'15 ,~
~ ,~ ~ c~ o S ~ ~ o ~r~ ou~ ~o co 5 a ~::
o o ~1 U) ~ ~ ~ r~ oo ~ ,, V ~ ~ ~ coco ~0 ~ r~
,, ,1 c) 5~ a ~ s~ ~ ~
~ ~. a~
O
,~ ~ ~ ~ ~ ~ Z O oa~
o o ~n o o o m ~ m o oo P- t~ H Z m The catalyst can be shown to be e~ually directive with other feed types and other operating conditions. The - catalyst can be used without the clay matrix or it can be mixed with other clays or binders as economically pre~er-able. The proportion of clay to catalyst can be varied also to achieve the optimum.
The liquid space velocity can be varied ~rom the 2.0 employed above to as low as 0.5 or as high as 6.5 with appropriate modifications in the opera~ing temperature and conditions.
The used catalyst becomes deactivated by coke (carbon) deposition, but it is readily regenerable by controlled oxidation of the deposit with a controlled at-mosphere of low percentages of oxygen in steam or in nitrogen. Because of the uniform pores of the product of the invention, regeneration is more uniformly and completely possible. Consequently the catalyst is regenerated essen-tially to its original selectivity and activity.
Further modifications of the catalyst may be accomplished b~ utilizing the ion exchange properties of the product of the invention. Manganese, magnesium, rare earths, especially lanthanum, and mixed rare earths are introduced into the structure in place of alkali by ion exchange.
The catalyst of the invention can be modified (promoted) with one or more metals to derive a catalyst useful for catalytic reforming. The spray dried product derived in the first paragraph of the description of the preparation of the FCC (fluid cracking catalyst) is further treated by methods known in the art so as to impregnate or ~2~8~L3 ion exchange the catalyst with platinum, for example, as platinum amine chloride. The treatment is effected in such a way as to attain a 0.5~ platinum content. The platinum-containing catalyst is dried and reduced in a hydrogen atmosphere at 200C (392F). The reduced catalyst is then coated with sufficient perrhenic acid solution to attain a level of 0.3% Re in and on the catalyst. To reduce the salts to the metallic form, the salt-impregnated càtalyst is heated to 250 to 300C in a hydrogen flow. The metals in and on the catalyst now comprise 0.5% Pt and 0.3~ Re in reduced form. The catalyst at this point is suitable for use in the reforming operation and is evaluated in equipment well known in the art as follows:

~3~3~L3 U~
O ~ O ~I N ~1 ~
lS') lx~ C10 U~
~ ~r o ~ oo ~r ~ o o O ~ ~1 ~ ~ ~ ~ ,~
~ ~ C~
o O

O rl ta 1 N 1.~ 0 ~) 00 Il') O ........
In O'~ ~ O ~ ~ ~ ~r ~ ~r 1~ ~

o ~ Q) a~ ~ o h 5~
u~ o u~ h S~ h ~ ~1 O ~ o " ~ ~ ~ ~ o O
~ 3 ~ 3 F~
O rl ~ h O
O O
u~ m c~
~n P~

~Z~ 3 The used catalyst can be regenerated by removal of coke and the activity is res-tored -to that of fresh cata-lyst. The use and regeneration can berepeated with the same results of high activity and selectivity because of the high thermal stability of the catalyst of the invention.
Space velocities that the catalyst will efectively permit are in the range 0.5 to 4.6 liquid/vol cat/hour.

This is an example of the preparation of a hydrous amorphous aluminosilicate powder of the invention where a heel of sodium aluminosilicatewas used às the core for the particles making up the powder.
A heel was made by diluting 1166 ml of the aquasol product of Example 3 (specific surface area 135 m2/g) in the Na form (pH 10.4) containing 10.72% solids, with hot watex to complete a total volume of 3 liters. Thus the heel was

4.16% solids and contained 125 g of sodium aluminosilicate.
The heel was heated to 100C and the pH was measured (pH 10).
When the heel reached 100C, the feed solutions of Example 1 were added each at a rate of 12 ml/min in the manner des-cribed in Example 1 while keeping the temperature of the heel at 100C _ 1C and the pH at 10.4 + 0.1. The pH was kept constant by periodically adding IRC-84-S ion e~change resin. A total of 3980 ml of each of the feed solutions and 1360 g of resin were used. The ~uild-up ratio ~BR) for this first build-up step was therefore 8.96. Build-up ratio is calculated by dividing the total amount of solids in the feed solutions added during the process by the amount of solids present in the heel before starting the addition.
The build-up ratio calculated above and the S

~2~3 (specific sur~ace area initially) determined independently by measurement were used to calcula-te the final specific surface area (SF) with the following formula:

3 r 3 r 2 ~BR 135 ~ 1 = 65 m /g Using the formula d = 6000 DxS
where d i5 the diameter of the particles in nanometers where D is the density of the particles g/cc where S is the specific surface area in m2/g of the particles.
The diameter of the final particles was calculated as follows:

d = 2665 = 42 nanometers.

At the end of the addition the slurry was filtered first through cloth and then through ilter paper to separate the ion exchange resin from the aquasol.
The volume of the product recovered was 9700 ml.
The concentration was 11.76 g solids per 100 ml. This concen-tration was determined by evaporating a weighed sample todryness, calcining the residue and reweighing.
Chemical analysis of the sol gave the following results: 10.5 g SiO2/100 ml, 1.64 g AlO2/100 ml and 0.854 g Na/100 ml. A sample was dried on steam and the specific surface area as measured by the Flow Method of nitrogen adsorption was 70 m2/g. An electron micrograph of the sol showed discrete~ dense spherical particles with a uniform particle size distribution, a weight average diameter of 38 nanometers and a number average diameter of 36 nanometers.
Standard deviation in both cases was 5 nanometers.

~3~3~3 Because of limitations in the size of th~ vessel and the feed concentration, the above particle build up was continued in a second step. Based on an initial surface area of 70 m2/g, it was calculated that a build-up ratio (BR) of about 5 would be needed to attain a specific surface area of about 40 m2/g. The particle size calculated from SF = 40 was 65 nanometers.
A heel for the second s~ep of the build up was prepared by diluting 850 ml of the sol of concentration 11.76 g solids/100 ml just described with hot tap water to a total volume of 5 liters. The heel was therefore 2%
solids and contained a total of 100 g of sodium aluminosilicate.
The heel was heated to 100C and feed solutions were added each at a rate of 6 ml/min while keeping the pH
constant at 10.3 ~ 0.2 with the periodic addition of ion exchange resin IRC-84-S. The two feed solutions were the same used in the first build-up step, aqueous silicate solu-tion 20 g SiO2/100 ml and aqueous aluminate solution 5 g NaAlO2/100 ml.
A total of 1640 ml of each of the feed solutions and 560 g of ion exchange resin were used. At the end of the addition, the slurry was filtered first through cloth and then through filter paper to separate the ion exchange resin from the aquasol.
The volume of the product recovered was 7600 ml.
Analysis of the product gave the ~ollowing results:
Concentration = 6.96 g solids/100 ml SiO2 = 5.31 g/100 ml AlO2 = 0.87 g/100 ml Na = 0.466 g/100 ml Specific Surface Area = 46 m /g.

~3~3~L3 An electron micrograph of the sol showed discrete, dense spherical particles with a uniform particle size dis-tribution, a weight average diameter of 65 nanometers (standard deviation = 5 nanometers) and a number average diameter of 64 nanometers (s-tandard deviation = 6 nanometers).
The sodium aluminosilicate aquasol was converted to the ammonium form by passing it through an ion exchange column packed with wet Dowex 50W-X8 ion exchange resin in the NH4+ form. pH of the NH4+ sol thus formed was 9.5 The sol was vacuum drum dried under the same con-ditions given in Example 2 and the dry power obtained was analyzed for pore size distribution and pore volume by nitrogen adsorption-desorption as described in Example 1.
The results obtained are as follows:
Experimental average pore diameter = 150 A
Pore Volume = 0.306 ml/g.
The powder had a narrow pore size distribution:
both the upper (229 A) and the lower limit (110 A) of pore size for 90% of the pore ~olume were within 40% of the median pore diameter (180 A).

The powder of Example 5 was tested for its ability to catalyze the synthesis of methylamines. A continuous flow reactor was used in which ~H3 and methanol ~ere pumped continuously through a 1" tube containing 50 g of powder.
Feed rate used for liquid methanol was 1,50 cc/min, feed rate for ammonia gas, 1100 cc/minO The tube was kept at a constant temperature of 450C and at a constant pressure of 1 atm. The exit and inlet streams of the tube were analyzed with a gas chromatograph and the yieIds of methyl- -amines and the conversion of methanol determined.

The operation was repeated using commercial Davison silica-alumina gel Grade 970, a trademark o~ the Davison Chemical Division of W. R. Grace & Co., with about the same alumina content of our sample. T~.e re~sults ob-tained with both catalysts are as ~ollows:

.

. - 67 -~*~

o u~ ~ o ) ~rl ~ a~
~ 0 a c~
o o rl ~ ~ ~ r o H C~ 1 N Y
U~ q~
O
O O

q~
a) o S~ ~
~a o ~ aJ ~
O ~ rl U~ rl ~ ~
~ ~ O

O ~ O
O ~ ~
a ~ h ~;Z38~3 Thus, -the resul-ts show that a composition of this - inventi~n gave higher methanol conversion, higher desirable monomethylamine production and more favorable product dis~
tribution than standard commercial silica-alumina gel.
~XAMPLE 7 This is an example of the preparation of an amorphous aluminosilicate powder of the invention using a freshly prepared sol of silicic acid and a solution of sodium aluminate as reactants and a heel of water.
A heel of 1.5 liters of water was heated to re-flux at 100C. To this heel, simultaneously and separately, was added (a) 1200 ml of 2~ silicic acid solution prepared from "F" grade sodium silicate, which contained 28.6~
SiO2 content, then passed through a column of Dowex 50W~-X8 cation exchange resin in the hydrogen form. The resulting silicic acid effluent contained 2% SiO2 and had a pH of about 3.2 and (b) 1200 ml of a sodium aluminate solution (2.7 g NaAlO2 per 100 ml) prepared by dissolving 42 g of NaA1~2 (74% reagent) in water and diluting to volume. The rate of addition of each was 200 ml per hour. During the addition of the two feed solutions, the temperature was maintained at 100C and the pH at 11.3 + 0.2 by adding IRC-84-S ion exchange resin. The resulting sol was cooled, deionized with Amberlite I~C~84-S in the hydrogen form by stirring this resin with the sol until the pH reached 7.6.
The resulting 3800 ml oE product was a stable sodium aluminosilicate sol containing 1.08 g solids per 100 ml. Chemical analysis of the resulting sol indicated that it contained 0.47 g SiO2/100 ml, 0.39 g AlO2/100 ml and 0.24 g Na/100 ml. Thus, the resulting product was an .23~3 aluminosilicate sol having the empirical formula NaAlO2-SiO2.
An electron micrograph of the sol showed discrete spheres of uniform diameter. The weight average diame-ter is 13 nano-meters (standard deviation 4 nanometers) and the number average diameter is 11 nanometers (standard deviation 3 nanometers).
The sol was converted to the ammonium form and spray dried in the manner describ~d in Example 1. The powder obtained was analyzed as in Example 1.
The results obtained were as follows:
Specific surface area: 280 m2/g Experimental average pore diameter: 57 A
Pore volume: 0.3995 ml/g.
Median pore diameter was 51 A. Ninety percent of the volume of the pores was constituted of pores ranging in diameter from 32 A to 68 A (within + 40% of the median pore diameter).

The usefulness of the product of Example 7 for the isomerization operation can be shown by this example~
The procedure of Example 4 is followed with the product of Example 7, except that a paste is made to a consistency for extrusion. The paste is extruded into 1/8"
x 1/8" cylinders. The cylinders are impregnated with pro-moters, 0.5% Pt and 0.2% Re and the impregnated catalyst is reduced to form the respective metals. The catalyst is then given a typical isomerization test in small scale equipment as follows:

Charge: Pentane~ and ~exanes - HDS treated.
Condition~:
Tempera-ture 300 to 400 Pressure 3 psiæ
Space velocity 3.0 LVH
- H2 to oil~ mole ratio 0.1 ~o 0.5:1 Components, wt percent Feed Product C4 and llgh~er 002 1.0 Isopentane 24.8 39.9 n-Pentane 21~4 10.8 2,2-dimethylbutane 1.0 16.3 2~3-dimethylbutane 2.9 1~.5 Cyclopentane 1~5 1.1 2-methylpentane 14.0 12.5 3-methylpe~tane 12.3 6.9 n-Hexane 13.1 4.2 Benzene 1.6 Methyl cyclopentane 1~8 1~3 Cyclohex~ne 0.0 1.0 Research Octane No.72.0 85.0 The catalyst shows excellent ~tability and con-tinued selectivity.

Thi~ is an example o~ the preparation of ~n amor-phous aluminosilicate powder of this in~ention with silica as the particle nucleus or core.
Three thousand gram~ of a 50~ by ~eight, 60 nano-meters ~article si~e silica sol heel ~s heated to 100C and the pH is ad~usted to 10.3 with sodlum hydroxide. ~he ~ilica sol used is commercially availa~le under the trade mark o~

3~

Nalcoag 1060 from the Nalco Chemical Company of Oak Brook, Illinois. Feed solutions and ion exchange resin are added in the manner described in Example 1 and sodium silicate and sodium aluminate, each added at a rate of 6 ml/min while keeping the heel at 100C. The two feed solutions of Example 1, aqueous sodium silicate solution 20 g SiO2/100 ml and aqueous sodium aluminate solution 5 g NaAlO2/100 ml, are used. The heel is kept at pH 10.3 + 0.1 by periodic additions of IRC-84-S resin.
A total of 340 ml of sodium silicate solution, 340 ml of sodium aluminate solution and 117 g of resin are used. At the end of the addition, the hot colloidal solution obtained is filtered first through cloth and then through filter paper to separate the ion exchange resin from the aquasol.
The resulting product is 3010 ml of a stable sol made of silica particles coated with sodium aluminosilicate, of pH 10.7 containing 43 g or solids per 100 ml solution.
Solids concentration is determined as explained in Example 1.
Dry powder is obtained by drying the sol. The surface area of the powder is measured by nitrogen adsorption using the flow method. The specific surface area thus measured is 40 m2/g An electron micrograph of the sol shows discrete spheres of uniform diameter. Average diameter is about 65 nanometers.
The sol obtained is converted to the ammonium form by passing it through an ion exchange column packed with wet Dowex 50W-X8 ion exchange resin in the NH~ form as ex-plained in Example 1.

~L~2~ 3 The aquasol in -the ammonium form thus formed is spray dried as described in Example 1 using the same spray drying condi-tions. Powder samples are collected in the cyclone and chamber collectors. Total product collected is 1035 g.
Electron micrographs of the spray dried powder showed spheroidal aggregates with an average diameter of about 21 microns.
Surface area and pore volume, pore diamater and pore size distribution analysis of the spray dried powder are made by the nitrogen absorption-desorption method used in Example 1.
Results obtained were as follows:
Specific Surface Area 40 m2/g Experimental Average Pore Diameter 155 A.
The arithmetic probability plot of the pore dia-meter versus pore volume data computed by the PORDIS program shows a median pore diameter of 150 A. Ninety percent of the volume of the pores is constituted of pores ranging in O O
diameter from 108 A to 202 A. Only 5% o~ the pores are larger than 202 A. This pore fraction is smaller than 280 A.

This is an example of the preparation of an amor-phous aluminosilicate catalyst of the invention with a zirconia heel as the particle nucleus.
One thousand grams of 10~ weight, 25 nanometers particle size zirconia aquasol is used as a heel. The sol is made of spherical particles with a uniform particle size distribution. The pH of the sol is 3.5. One hundred milli-liters of a sodium citrate solution containing 2.8 g of ~3~L3 sodium citrate are added to the sol at a rate of about 12 ml/min with strong agitation. The resulting sol is 2.8 g of sodium citrate/100 g ZrO2. The pH of the sol is raised to 10.3 with NaOH.
The two feed solutions of Example 1, aqueous sodium silicate solution 20 g SiO2/100 ml and aqueous sod-ium aluminate solution 5 g NaAlO2jl00 ml and ion exchange resins are added as described in Example 1 at a rate of 4.3 ml/min for the silicate and 5.9 ml/min for the aluminate while keeping the heel at 100C. The heel is kept at pH
10.3 + 0.1 by periodic additions of IRC-84-S ~esin.
A total of 205 ml of sodium silicate solution, 286 ml of sodium aluminate solution and 70 g of resin are used. At the end of the addition the hot colloidal solu-tion obtained is filtered first through cloth and then through filter paper to separate the ion exchange resin from the aquasol.
The resulting product is 1010 ml of stable sol made of zirconia particles coated with sodium aluminosilicate, of pH 10.7 containing 11.5 g solids/100 ml solution. Solids concentration is determined as explained in Example 1.
A sample of this sol is dried and the dry powder obtained is used for measurement of surface area by nitrogen adsorption using the flow method. Specific surface area - thus measured is 37 m2/g. An electron micrograph of the sol shows discrete spheres of uniform diameter. Average diameter is about 30 nanometers.
The sol obtained is converted to the ammonium form by passing it through an ion exchange column packed with wet Dowex 50W-X8 ion exchange resin in the NH4 form as des-cribed in Example 1. The aquasol in the ammonium form thus ~3~3 formed is spray dried as described in Example 1 using the same spray drying conditions. Powder samples are collected in the cyclone and chamber collectors. Total product col-lected is 81 g.
Electron micrographs of the spray dried powder showed spheroidal aggregates with an average diameter of about 10 micrometers.
Surface area and pore volume, pore diame~er and pore size distribution analysis of the spray dried powder are made ~y the nitrogen absorption-desorption method of Example 1.
The specific surface area is 35 m /g and the ex~
perimental average pore diameter is 120 A.
The arithmetic probability plot of the pore dia-meter versus pore volume data computed by the PORDIS pro-gram shows a median pore diameter of 110 A. Ninety percent of the volume of the pores is constituted of pores ranging in diameter from 77 A to 143 A. Only 5~ of the pores are O O
larger than 143 A. This pore raction is smaller than 210 ~.
EXAMP~E 11 This is an example o F the preparation of an amor-phous aluminosilicate catalyst of this invention with an eta alumina heel as the particle nucleus.
One thousand grams of 10~ weight, 50 nanometer particle size eta alumina aquasol is used as a heel. The sol is made of spherical particles with a uniform particle size distribution. The pH of the sol is 3.5. One hundred milliliters of a sodium citrate solution containing 5 g of sodium citrate are added to the sol at a rate of about 12 ml/min with strong agitation to yield a sol with 0.55 g ~1*~J3I~3 sodium citrate/100 g A12O3. The pH of the sol is raised -to 10.3 with NaOH.
The two feed solutions of Example 1, aqueous sodium silicate solution 20 g SiO2/100 ml and aqueous sodium aluminate solution 5 g NaAlO2/100 ml and ion ex-change resins are added as descxibed in Example 1 at a rate of 4.3 ml/min for the silicate and 5.9 ml/min for the aluminate while keeping the heel at 100C. The heel is kept at pH 10.3 + 0.1 by periodic additions of IRC-84-S
resin.
A total of 97 ml of sodium silicate solution, 133 ml of sodium aluminate solution and 50 g of resin are used. At the end of the addition, the hot colloidal solu-tion obtained is filtered first through cloth and then through filter paper to separate the ion exchange resin from the aquasol.
The resulting product is 950 ml of stable sol made of alumina particles coated with sodium aluminosilicate, of pH 10.7 containing 9.9 g solids/100 ml solution. Solids concentration is determined as in Example 1.
A sample of this sol is dried and the dry powder obtained is used for measurement of surface area by nitrogen adsorption using the flow method. Specific surface area thus measured is 34 m2/g. An electron micrograph of the sol shows discrete spheres of uniform diameter. Average diameter is about 55 nanometers.
The sol obtained is converted to the ammonium form by passing it through an ion exchange column packed with wet Dowex 50W-X8 ion exchange resin in the NH4 form as in Example 1.

~L ~ 2 ;3 ~ 3 The aquasol in the ammonium ~orm thus ~ormed is spray dried as described in Example 1 using the same spray drying conditions. Powder samples are collected ~n the cyclone and chamber collectors. Total product collected is 76 g. Electron micrographs of the spray dried powder showed spheroidal aggregates with an average diameter of about ll micrometers.
Surface area and pore volume, pore diameter and pore size distribution analysis of the spray dried powder are made by the nitrogen absorption-desorption method used in Example 1.
The specific surf~ce area was 30 m2/g and the experimental average pore diameter was 130 A.
The arithmetic probability plot of the pore dia-meter versus pore volume data computed by the PORDIS pro-gram shows a median pore diameter of 145 A. Ninety percent of the volume of the pores is constituted of pores ranging O O
in diameter from 102 A to 189 A. Only 5% of the pores are larger than 189 A. This pore fraction is smaller than EXAMP~E 12 This is an example of the preparation of an amor-phous aluminosilicate catalyst of the invention with a titania heel as the particle nucleus.
One thousand grams of 10~ weight, 10 nanometers particle size titania aquasol was used as a heel. The sol is made of spherical particles wi-th a uniform particle si~e distribution. The pH of the sol is 3.5. One hundred milli-liters of a sodium citrate solution containing 135 g of sodium citrate are added to the sol at a rate of about ~Z38~3L3 12 ml/min with strong agitation to yield a sol with 13.5 g sodium citrate/100 g Tio2. The pH of the sol is raised to 10.3 ~ith NaOH.
The two feed solutions of Example 1, aqueous sodium silicate solution 20 g SiO2/100 ml and aqueous sodium aluminate solution s g NaAlO2/100 ml and ion exchange resins are added as described in Example 1 at a rate of 4.3 ml/min for the silicate and 5.9 ml/min for the aluminate while keeping the heel at 100C. The heel is kept at pH
10.3 + 0.1 by periodic additions of IRC-84-S.
A total of 641 ml of sodium silicate solution, 894 ml of sodium aluminate solution and 220 g of resin are used. At the end of the addition, the hot colloidal solu-tion obtained is filtered ~irst through cloth and then through filter paper to separate the ion exchange resin from the aquasol.
The resuling product is 1980 ml o~ stable sol made of ~itania particles coated with sodium aluminosilicate, of pH 10.7 containing i0.5 g solidsjlO0 ml solution. Solids concentration is determined as in Example 1.
A sample of this sol is dried and the dry powder obtained is used for measurement of surface area by nitrogen adsorption using the Flow Method. Specific surface area thus measured is 94 m2/g. An electron micrograph of the sol shows discrete spheres of uniform diameter. Average dia-meter is about 15 nanometers.
The sol obtained is converted to the ammonium form by passing it through an ion exchange column packed with wet Dowex 50W-X8 ion exchange resin in the NH4 form as des-cribed in Example 1. The aquasol in the a~monium form thus formed is spray dried as described in Example 1 using the 38~3 same spray drying conditions. Powder samples are collected in the cyclone and chamber collectors. Total product col-lected is 165 g.
Electron micrographs of the spray dried powder showed spheroidal aggregates with an average diameter of about 8 micrometers.
Surface area and pore volume, pore diameter and pore size distribution analysis of the spray dried powder are made by the nitrogen absorption-desorption method used in Example 1.
The specific surface area was 95 m /g and the ex-perimental average pore diameter was 75 A.
The arithmetic probability plot of the pore dia-meter versus pore volume data computed by the POR~IS pro-gram shows a median pore diameter of 70 A. Ninety percent of the volume of the pores is constituted of pores ranging in diameter from 49 A to 91 A. Only 5% of the pores are O O
larger than ~1 A. This pore fraction is smaller than 170 A~
Thus, the porous powder compositions of this in-vention may be used for the hydrocracking of petroleum dis-tillates by contacting said compositions with said distillates, under conditions well known in the art.
It is to be understood that any of the components and conditions mentioned as suitable herein can be sub-stituted for its counterpart in the foregoing examples and that although the invention has been described in considera-able detail in the foregoing, such detail is solely for the purpose of illustration. Variations can be made in the invention by those skilled in the art without departing from ~0 the spirit and scope of the invention except as set forth in the claims.

3:~ 3 SUPPLEMENTARY DISCLOSURE
~_. . ..
Further to -the porous powders hav.Lng an ~lumino-silica-te c~ati.n~ with pores o-~ subst~ntially uniform si.ze, and the preparation thereo:f, described hereinbef~re, lt has now been foun~ that the present invention also pr~vides a uniformly porous powder composition comPrising porous aggregates of spheroidal ~articles which are 20 A to 250 A, with pore diameters of 20 A to 4~ A having a uniformity such that at least 90~ of the pore volume is made up of pores o~ from o.6D to 1.4D and pore diameters of 45 A to 2~0 A
having a uniformity such that at least 80~ o~ the pore volume is made up of pores of from o~6~ to l~lD, where D
is the median p~re diameter, The alumina silicates o~ this inventi.on are prepared by a process comprising:
(a) preparing a heel sol of discrete colloidal particles selected ~rom sodium, potassium or ammonlum aluminosilicate~ silica and one or more refractory metal oxides selected from the group consisting o~ titania.
aluminia~ zirconia, lanthana, thoria and rare earth metal oxides, said heel sol comprising particles o~ a substantially uniform diameter within the range o~ 2 to about 85 nano-meters, the lnitlal concentration i.n the heel sol of sodium, potassium, ammonium aluminosilicate or ~otal refractory metal oxides being at least 0.2~ by weigh-t with the partlcles stabilized against aggregation in the pH range 9 to 12;
(b) adding to said heel~ separately but simul-taneously, two feed solutions, one being a solution ~f sodium or potassium silicate having from 1 to 36 grams of silica per 10O cc~ or a sol of silicic acid containing ~rom 1 to 12~ sllica, the other being a solution of sodium or potassium aluminate containing from 1 to 15% alumina, said 3~3 feed solutions being added in relative rates and proportions to maintain a constant molar ratlo o~ Si:Al in the feed stream~
of from 1:1 to 19 1 with the rate of addition of silica not to exceed 10 grams of Sio2 per lO00 square meters of total surface area of particles in the heel sol per hour;
(c~ maintaining -the pH o~ the heel eol at a constant value between 9 and 12 by adding a cation exchange resin in the hydrogen or ammonium form until the particles in the heel sol have attained an increase in dlameter of at 10 least 1 nanometer and a maxium size of 90 nanome-ters;
(d) filtering the sol from (c) to remove the cation exchange resln and optionally ad~usting the concen-tration of the resulting aluminosilicate 901 to a solids content of up to 60~ by weight; and (e) drying the resulting substantially gel-free sol of particles havingan aluminosilicate surface to a powder by removing water at a rate at which no gelling will occur Accordingly~ the uniform size amorphous alumino-silicate particle sols of this invention are produced bysteps, a, b and c of the aforesaid process ~ollowed by re-moval of the exchange resin, The uniformity of sflid parti-cles is such that the maximum standard deviation of the particle size is 00 37d where d is weighted average particle size diameter.
Thus, the amorphous aluminosilicat2 sols of this invention have uniform particles of from 3 to 90 nanometers in diameter with a molar ratio of Si/Al of l-l to l9:1, said uniformity defined by particles having a maximum stan-dard deviation of 0.37d, where d is the weighted aver~ eparticle size diameter, ~8 .. .

The aforesald 901s are especially use~ul when the maximum standard deviation is 0.30d, The uniformity of the particles in the sols of this invention can also be expressed in ~ form based on the number average of particles rather than weight aver~ e, The uniformity based ~n particle number average is a maximum standard deviation of 0,4~d where d is the number average particle diameterO
The control of pH and the maximum addition rate of silicate and aluminate (lOg of SiO2 per lOOQ s~uare meters of surface area per hour~ results in the alumino-silicate p~rticles be~ng of the uniformity described herein.
The present invention is further illustrated by the following example, Example 1~
This was an example of the preparation of a hydrous amorphous aluminosilicate powder of the invention where a heel of silica sol prepared in situ was used in the apparatus described in Example 1 to form the core of the particles of this invention, A 1~ silica sol heel was prepared in situ at 70C and pH of 9 by diluting 127 ml of 20~ SiO2 sodium silicate JM(SiO2/Na20 weight ratio ~.25) a total volume of 3000 ml with hot tap water to make 1,270 liters of 1% SiO2 heel (12.7 g SiO2 in 1270 ml of solution~, The heel was heated to 70C and then deionized to pH 9 -~ 0~1 with ~0 g of ion exchange resin Amberlite~ IRC 84-S, Feed solutions were added in the manner ex~lained in Example 1 to buildup with sodium silicate and sodium aluminate, the sodium silicate solution at a rate of 3~3 12 ml/min and the sodium alumlnate solution at a rate o~
27 ml/min whlle simultaneously heating the heel to 100C, Heating ~rom 70 to lOO~C took about ~8 minutes, The two feed solutions of Example 1, aqueous sodium silicate solu-tion 20 g SiO2/100 ml and aqueous sodium alum-lnate solution

5 g NaA102/100 ml were used, In 4 minutes the pH of the heel rose to 11~3 due to the alkalinity o~ the feed solu-tions being added~ From this point on the heel was kept at 11,3 + 0,1 by periodic additions of IRC-84-S resin, lo A total of 3770 ml of sodium silicate solut~on~
8420 ml of sodium aluminate solution and 1450 g o~ resin were used, At the end o~ the addition the hot colloidal solution obtained was filtered f~rst ~hrough cloth and then through filter paper to separate the ion exchange resin from the aquasol, The resulting product was 11.8 llters of a stable sodium aluminosilicate sol containing 10 g/100 ml solution, Solids concentration was determined as disclosed in Example 1. Chemlcal analysis of the resulting sol indi-20 cated that it contained 4~98 g SiO2/100 ml~ 2.47 gA102/100 ml and 1.01 g Na/100 ml, Thus the resulting product Nas an aluminosillcate sol having the emplrical formula NaA102,1.98SiO2, nH20. The speci~ic surface area of the sol was determined after the sol was dried by measuring the surface area by nitrogen a~sorption using the flow method, Specific sur~ace area thus measured was 122 m2/g, An electron micrograph o~ the sol showed discrete spheres of uniform dlameter, We~ght a~erage diameter was 30 26,6 nanometers, The standard deviat~Qn was 4,7 nanometers, The sol was converted to the ammonium form by ion exchange in the manner d2scribed ln Example 1, -83_ . , .

The a~monium aluminosllicate thus formed h~d a p}I o~ 9 and it was spray dried in a Bowen Engineering, Inc.
No. 1 Ceramic Dryer using a two-fluid nozzlo type 59-BS, Operating condltions for spray drying were the ~ollowing:
Feed Weight % solids 10 Total feed 3000 ml Feed rate 100 ml/min Inlet temp, 350C
Outlet temp, l90~C
AtQmizing pressure 5 psig Powder samples were collected in the cyclone and chamber collectors, Total product collected was 117 g ~or 39~ recovery on a wet basis.
Nlnety-~our g of the cyclone product w~ e sus-pended in 1 liter of saturated ammonium carbonate solution at room temperature and stirred gently for 5 hours, The slurry was centrifuged and the cake obtained was reslurried in a 50:50 mixture of concentrated ammonium and H20, The washing operation was repeated four times and the cake obtained was dried in vacuum oven at 80C overni~ht, The dry powder was analyzed for sodium and lt contained 0,Z7 Na by weight, The extraction operation was then repeated and the dry powder obtained was analyzed again ~or Na and gave 0,12% Na by weight, Surface area and pore volume, pore diameter and pore size distribution analysis of the spray dried powder were made by a ni~rogen absorption-desorpotion method using a Micromer~t~c ~ 2100-D apparatus, ~icromerit~cs ~ 2100 D
ls the trademarX of Micromeritics Instrument ~orporat~on of Norcross, Georgia, for an Orr Surface-Area Pore-Volume r --84 ~ .

,3æ3 3 Analyzer, Reults were obtained a~ ~o~lows:
Specific surface area 122 m2/g Median pore diameter 61 A
Pore volume o,3~5 ml/g Pore ~olume distribution analysis was made ba3ed on the B~ F. Roberts method (J, Colloid and Interface Science 23, 266 (1967) ) and the results computed and plott~d using the PORDIS-PORTL computer program.
Eighty-four percent of the volume o~ the pores was constituted of pores rang~ng in diameter ~rom o.6 to 1,4 of the median pore diameter.
m e powder was mixed with a rare earth 2eolite Y
and proved in testing to be an excellent catalyst ~or the cat-cracking of petroleum.

~' r-`

Claims (68)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A porous powder composition comprising porous aggregates of spheroidal particles of from 3 to 90 nanometers which particles are uniform in size and nonporous to nitrogen and contain:
(a) a core of silica, aluminosilicate or one or more refractory metal oxides selected from alumina, zirconia, titania, thoria and rare earth oxides;
(b) a coating around said core of at least 0.5 nanometer in depth of an amorphous hydrous aluminosilicate compound having a molar ratio of Si:Al from 1:1 to 19:1 and comprising one or more cations selected from sodium, potassium, ammonium, hydrogen and Groups I to VIII metals selected from Cs, Li, Mg, Rb, Ca, Sr, Ba, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Y, Zr, Nb, Mo, Th, Tc, Ru, Rh, Pd, Ag, La, Ce, rare earth metals, Hf, Ta, W, Re, Os, Ir, Pt, Au, Sn, Cd, Bi and Sb; and (c) a surface layer over said coating of 0 to 15%
by weight o the core and coating of one or more of a metal or metal oxide in which the metal of the metal or metal oxide is selected from Cs, Li, Mg, Rb, Ca, Sr, Ba, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, La, Ce, rare earth metals, Hf, Ta, W, Re, Os, Ir, Pt, Au, Sn, Cd, Bi and Sb; said powder composition having a specific surface area of 30 to 750 m2/g, a bulk density of 0.5 g/cc or more and a uniform pore diameter between the spheroidal particles in the range of 20 to 150.ANG. said uniformity being such that 90% of the pore volume is of pores of from 0.6D to 1.4D in size, where D is the median pore diameter.

2. The composition of Claim 1 wherein the refractory metal oxides of the core are selected from the group consisting of alumina, zirconia, titania, and rare earth oxides.

3. The composition of Claim 1 wherein the core is aluminosilicate.

4. The composition of Claim 1 wherein the core is silica.

5. The composition of Claim 1 characterized by having a bulk density of 0.5 to 0.9 g/cc.

6. The composition of Claim 1 in which the aggregates are spheroidal with an average diameter within the range of 5 to about 200 microns.

7. The composition of Claim 1 wherein the cation of the aluminosilicate coating is selected from ammonium and hydrogen and the Group I to VIII metals.

8. The composition of Claim 1 wherein the cations of the aluminosilicate coating are selected from ammonium and hydrogen.

9. The composition of Claim 1 wherein the cation of the aluminosilicate coating is hydrogen.

10. The composition of Claim 1 wherein the uni-formity of the pores is defined by 90% of the pore volume being of pores of from 0.7D to 1.3D in size.

11. The composition of Claim 1 wherein the cation of Groups I to VIII are selected from the group consist-ing of Ca, Mg, Mn, Ru, Rh, Pd, La, W, Re, Ir, Pt, Ce and rare earth metals.

12. The composition of Claim 1 wherein the metal or metal oxide coating is 1 to 8% by weight of the powder.

13. The composition of Claim 1 wherein the metal or metal oxide coating is 0%.

14. The composition of Claim 1 wherein the ratio of Si:Al is from 1:1 to 6:1.

15. The composition of Claim 1 wherein the ratio of Si:Al is from 3.5:1 to 6:1.

16. The composition of Claim 1 wherein the metal or metal oxide surface layer is selected from the group consisting of Ca, Mg, Mn, Ru, Rh, Pd, La, W, Re, Ir, Pt, Ce, the rare earth metals and mixtures thereof.

17. The porous powder composition of Claim 1 uniformly mixed with a crystalline aluminosilicate zeolite such that the mixture is 5 to 50% by weight crystalline aluminosilicate zeolite and 95 to 50% by weight of said powder.

18 The porous powder composition of Claim 1 uniformly mixed with a crystalline aluminosilicate zeolite such that the mixture is 10 to 25% by weight crystalline aluminosilicate zeolite and 90 to 75% by weight of said powder.

19. A method for the preparation of the composi-tion of Claim 1 comprising:
(a) preparing a heel sol of discrete colloidal particles selected from sodium, potassium or ammonium aluminosilicate, silica, and one or more refractory oxides selected from alumina, zirconia, lanthana, thoria, titania and other rare earth oxides, said particles having a substantially uniform diameter within the range of 2 to about 85 nano-meters, said aluminosilicate having a molar ratio of Si:Al of from 1:1 to 19:1, the initial concentration in the heel sol of sodium, potassium, ammonium aluminosilicate or re-fractory metal oxide being at least 0.2% by weight, with the particles stabilized against aggregation in the pH range 9 to 12;
(b) adding to said heel, separately but simultane-ously, two feed solutions, one being a solution of sodium or potassium silicate having from one to 36 grams of silica per 100 cc, or a sol of silicic acid containing from 1 to 12% silica, the other being a solution of sodium or potas-sium aluminate containing from 1 to 15% alumina, said feed solutions being added in relative rates and proportions to maintain a constant molar ratio of Si:Al in the feed streams of from 1:1 to 19:1 with the rate of addition of silica not to exceed 10 grams of SiO2 per 1000 square meters of total surface area of particles in the heel sol per hour;
(c) maintaining the pH of the heel sol at a constant value between 9 and 12 by adding cation exchange resin in the hydrogen form, maintaining the temperature of the heel sol at from 50 to 100°C until the particles in the heel sol have attained an increase in diameter of at least 1 nanometer and a maximum size of 90 nanometers;
(d) filtering the sol from (c) to remove the cation exchange resin and adjusting the concentration of the resulting aluminosilicate sol to a solids content of 1 to 60% by weight; and (e) drying the resulting substantially gel-free sol of particles having an aluminosilicate surface to a powder by removing water at a rate at which no gelling will occur.

20. The method of Claim 19 wherein the pH of the heel sol during the addition of the feed solutions is main-tained between 10 and 10.5.

21. The method of Claim 19 wherein the discrete colloidal particles of the heel sol are silica.

22. The method of Claim 19 wherein the discrete colloidal particles of the heel sol are a sodium, potassium or ammonium aluminosilicate sol.

23. The method of Claim 19 wherein the discrete colloidal particles of the heel sol are one or more refractory oxides.

24. The method of Claim 19 wherein the refractory oxides in the heel sol are selected from the group consist-ing of alumina, zirconia, lanthana and titania.

25. The method of Claim 19 wherein the sodium or potassium silicate solution is 15 to 25% by weight of silica.

26. The method of Claim 19 wherein the sol from (d) is ion-exchanged to partly or completely replace the sodium or potassium ions by hydrogen or ammonium ions before the drying step.

27. The method of Claim 26 wherein the hydrogen or ammonium ions are replaced, completely or in part, with one or more metal ions selected from the group Cs, Rb, Li, Mg, Ca, Sr, Ba, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, La, Ce, rare earth metals, Hf, Ta, W, Re, Os, Ir, Pt, Au, Bi, Cd, Sn, Sb and mixtures thereof.

28. The method of Claim 26 wherein the dried composition after (e) is impregnated with a solution com-prising one or more metal cations selected from Cs, Rb, Li, Mg, Ca, Sr, Ba, Sc, Ti, V, Cr, Mn, Fe, Co, Hi, Cu, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, La, Ce, rare earth metals, Hf, Ta, W, Re, Os, Ir, Pt, Au, Bi, Cd, Sn and Sb and drying.

29. The method of Claim 26 wherein metal cations are introduced by adding a solution of a metal salt to the sol from (d) with intensive agitation at the point of mixing.

30. The method of Claim 26 wherein the ammonium ions are replaced, completely or in part, by exchanging the ammonium ions of the sol with metal ions on a sulfonic acid type ion exchange resin.

31. In a catalytic process for petroleum refining under conventional conditions, the improvement wherein the catalyst composition of Claim 1 is used.

32. The process of Claim 31 wherein the mixture of Claim 17 is used.

33. The process of Claim 31 wherein the mixture of Claim 18 is used.

CLAIMS SUPPORTED BY THE SUPPLEMENTARY DISCLOSURE

34. A porous powder composition comprising porous aggregates of spheroidal particles of from 3 to 90 nanometers which particles are nonporous to nitrogen and contain (a) a core of silica, aluminosilicate or one or more refractory metal oxides selected from alumina, zirconia, titania, thoria and rare earth oxides;
(b) a coating around said core of at least 0.5 nanometer in depth of an amorphous hydrous aluminosilicate compound having a molar ratio of Si:Al of from 1:1 to 19:1 and comprising one or more cations selected from sodium, potassium, ammonium, hydrogen and Groups I to VIII metals selected from Cs, Li, Mg, Rb, Ca, Sr, Ba, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Y, Zr, Nb, Mo, Th, Tc, Ru, Rh, Pd, Ag, La, Ce, rare earth metals, Hf, Ta, W, Re, Os, Ir, Pt, Au, Sn, Cd, Bi and Sb; and (c) a surface layer over said coating of 0 to 15%
by weight of the core and coating of a metal or metal oxide selected from Cs, Li, Mg, Ca, Sr, Ba, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, La, Ce, rare earth metals, Hf, Ta, W, Re, Os, Ir, Pt, Au, Sn, Cd, Bi and Sb; said powder composition having a specific surface area of 30 to 750 m2/g, a bulk density of 0.5 g/cc or more and sub-stantially uniform size pore diameters of from 20 .ANG. to 250 .ANG., with pore diameters of 20 .ANG. to 45 .ANG. having a uniformity such that at least 90% of the pore volume is made up of pores of from 0.6D to 1.4D and pore diameters of 45 .ANG. to 250 .ANG. having a uniformity such that at least 80% of the pore volume is made up of pores of from 0.6D to 1.4D, where D is the median pore diameter.

35. The composition of Claim 34 wherein the refractory metal oxides of the core are selected from the group consisting of alumina, zirconia, titania, and rare earth oxides.

36. The composition of Claim 34 wherein the core is aluminosilicate.

37. The composition of Claim 34 wherein the core is silica.

38. The composition of Claim 34 characterized by having a bulk density of 0.5 to 0.9 g/cc.

39. The composition of Claim 34 in which the aggregates are spheroidal with an average diameter with-in the range of 5 to about 200 microns.

40. The composition of Claim 34 wherein the cation of the aluminosilicate coating is selected from ammonium and hydrogen and the Group I to VIII metals.

41. The composition of Claim 34 wherein the cations of the aluminosilicate coating are selected from ammonium and hydrogen.

42. The composition of Claim 34 wherein the cation of the aluminosilicate coating is hydrogen.

43. The composition of Claim 34 wherein, in the range of 20 .ANG. to 150 .ANG. pore diameters, 90% of the pore volume is of pores from 0.6 D to 1.4 D.

44. The composition of Claim 34 wherein, in the range of 45 .ANG. to 250 .ANG. pore diameters, 80% of the pore volume is of pores of 0.6D to 1.4D.

45. The composition of Claim 43 wherein 90%
of the pore volume is of pores of from 0.7 D to 1.3 D.

46. The composition of Claim 34 wherein the cation of Groups I to VIII are selected from the group consisting of Ca, Mg, Mn, Ru, Rh, Pd, La, W, Re, Ir, Pt, Ce and rare earth metals.

47. The composition of Claim 34 wherein the metal or metal oxide coating is 1 to 8% by weight of the powder.

48. The composition of Claim 34 wherein the metal or metal oxide coating is 0%.

49. The composition of Claim 34 wherein the ratio of Si:Al is from 1:1 to 6:1.

50. The composition of Claim 34 wherein the ratio of Si:Al is from 3.5:1 to 6:1.

51. The composition of Claim 34 wherein the metal or metal oxide surface layer is selected from the group consisting of Ca, Mg, Mn, Ru, Rh, Pd, La, W, Re, Ir, Pt, Ce, the rare earth metal oxides and mixtures thereof.

52. The porous powder composition of Claim 34 uniformly mixed with a crystalline aluminosilicate zeolite such that the mixture is 5 to 50% by weight crystalline aluminosilicate zeolite and 95 to 50% by weight of said powder.

53. The porous powder composition of Claim 34 uniformly mixed with a crystalline aluminosilicate zeolite such that the mixture is 10 to 25% by weight crystalline aluminosilicate zeolite and 90 to 75% by weight of said powder.

54. In a catalytic process for petroleum refining under conventional conditions, the improvement wherein the catalyst of Claim 34 is used.

55. The process of Claim 54 wherein the mix-ture of Claim 52 is used.

56. The process of Claim 54 wherein the mix-ture of Claim 53 is used.

57. A method for preparing the porous powder composition of Claim 34 comprising:

(a) preparing a heel sol of discrete colloidal particles selected from sodium, potassium, or ammonium aluminosilicate, silica, and one or more refractory oxides selected from alumina, zirconia, lanthana, thoria, titania and rare earth oxides, said particles having a substantially uniform diameter within the range of 2 to about 85 nanometers, said aluminosilicate having a molar ratio of Si:Al of from 1:1 to 19:1, the initial concentration in the heel sol of sodium, potassium ammonium, aluminosilicate or refractory metal oxides being at least 0.2% by weight, with the particles stabilized against aggregation in the pH range 9 to 12;
(b) adding to said heel, separately but sim-ultaneously, two feed solutions, one being a solution of sodium or potassium silicate having from 1 to 36 grams of silica per 100 cc, or a sol of silicic acid con-taining from 1 to 12% silica, the other being a solution of sodium or potassium aluminate containing from 1 to 15% alumina, said feed solutions being added in relative rates and proportions to maintain a con-stant molar ratio of Si:Al in the feed streams of from 1:1 to 19:1 with the rate of addition of silica not to exceed 10 grams of SiO2 per 1000 square meters of total surface area of particles in the heel sol per hour;
(c) maintaining the pH of the heel sol at a constant value between 9 and 12 by adding cation exchange resin in the hydrogen form, maintaining the temperature of the heel sol at from 50° to 100°C until the particles in the heel sol have attained an increase in diameter of at least 1 nanometer and a maximum size of 90 nanometers;

(d) filtering the sol from (c) to remove the cation exchange resin and optionally adjusting the con-centration of the resulting aluminosilicate sol to a solids content of up to 60% by weight; and (e) drying the resulting substantially gel-free sol of particles having an aluminosilicate surface to a powder by removing water at a rate at which no gelling will occur.

58. The method of Claim 57 wherein the pH
of the heel sol during the addition of the feed solutions is maintained between 10 and 10.5.

59. The method of Claim 57 wherein the dis-crete colloidal particles of the heel sol are silica.

60. The method of Claim 57 wherein the dis-crete colloidal particles of the heel sol are a sodium, potassium or ammonium aluminosilicate sol.

61. The method of Claim 57 wherein the dis-crete colloidal particles of the heel sol are one or more refractory oxides.

62. The method of Claim 57 wherein the re-fractory oxides in the heel sol are selected from the group consisting of alumina, zirconia, lanthana and titania.

63. The method of Claim 57 wherein the sodium or potassium silicate solution is 15 to 25%
by weight of silica.

64. The method of Claim 57 wherein the sol from (d) is ion-exchanged to partly or completely replace the sodium or potassium ions by hydrogen or ammonium ions before the drying step.

65. The method of Claim 64 wherein the hydrogen or ammonium ions are replaced, completely or in part, with one or more metal ions selected from the groups Cs, Rb, Li, Mg, Ca, Sr, Ba, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, La, Ce, rare earth metals, Hf, Ta, W, Re, Os, Ir, Pt, Au, Bi, Cd, Sn, Sb, and mixtures thereof.

66. The method of Claim 64 wherein the dried composition after (e) is impregnated with a solution comprising one or more metal cations selected from Os, Rb, Li, Mg, Ca, Sr, Ba, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, La, Ce, rare earth metals, Hf, Ta, W, Re, Os, Ir, Pt, Ag, Bi, Cd, Sn, and Sb and drying.

67. The method of Claim 64 wherein metal cations are introduced by adding a solution of a metal salt to the sol from (d) with intènsive agitation at the point of mixing.

68. The method of Claim 64 wherein the ammonium ions are replaced, completely or in part, by exchanging the ammonium ions of the sol with metal ions on a sulfonic acid type ion exchange resin.