ES359879A1 - Impregnated catalysts - Google Patents

Abstract

A hydrogenation/dehydrogenation catalyst is prepared by a process which comprises calcining porous support material, contacting the calcined support material, without evacuation, with a solution of a hydrogenation/dehydrogenation constituent for a maximum of 30 minutes so that the resulting deposit of the constituent is concentrated on the surface of the support material, immediately drying the impregnated support material, calcining the dried impregnated support material in an oxidising atmosphere and reducing at least a portion of the hydrogenation/dehydrogenation constituent. The final step of reducing may be effected in a hydrocarbon conversion reactor, for example upon exposure of the catalyst to the conditions of its use in a hydrocarbon conversion process, for example hydrocracking or reforming. The support material may be a catalytically-active inorganic oxide material, for example silicaalumina, silica-titania, silica-zirconia or, preferably, a zeolite which may be natural or synthetic (numerous examples being listed in the specification) and which may have been treated to replace sodium cation thereof by an ion selected from hydrogen, ammonium, alkylammonium and arylammonium ions and ions of Group 1B to VIII metals, especially rare earth metals. The hydrogenation/dehydrogenation constituent may comprise a transition metal, for example a metal selected from Groups VIB and VIII exemplified metals are molybdenum, tungsten, cobalt, nickel, rhodium, palladium, osmium, iridium and platinum. The catayst may be in the form of extrudates having a diameter of from 1/32 to 3/16 inch and a length of between one and three times the diameter. Exemplified catalysts are rare earth-exchanged zeolite X containing platinum derived by impregnating with a solution containing either chloroplatinic acid and sodium hydroxide (Examples 1, 2 and 3) or chloroplatinic acid alone (Examples 4, 5 and 6), palladium derived by impregnating with a hydrochloric acid solution containing palladous chloride (Examples 7 and 8), tungsten, nickel and platinum derived by impregnating initially with an ammoniacal solution containing tungstic acid and nickel nitrate and, after an intermediate calcination, then with a solution containing chloroplatinic acid (Example 9), nickel derived by impregnating with a solution containing nickel chloride (Example 10), and palladium and platinum derived by impregnating with a solution containing palladium chloride and chloroplatinic acid (Example 11), and a palladium impregnated mixture of tungsten and nickel impregnated rare earth-exchanged zeolite X and tungsten and nickel impregnated silica-alumina, which catalyst is prepared by separately impregnating rare earth-exchanged zeolite X and silica-alumina each with an ammoniacal solution tungstic acid and nickel nitrate, forming a mixture of the impregnated zeolite and the impregnated silica-alumina, and impregnating the mixture with a solution of palladium chloride (Example 12). Data relating to density, pore volume, surface area and crushing strength of the catalysts are given in the specification.