DE19861356B4 - Method for testing the catalytic activity of solids exposed to a reaction gas - Google Patents

Abstract

The present method employs an arrangement for testing the catalytic activity of reaction gas-exposed solids, which i.a. comprises a receiving unit (1) having a plurality of recesses (7) for receiving a respective solid and a common gas supply and the individual recesses associated channels (8). This arrangement is operated according to the inventive method so that all solids are simultaneously exposed to the reaction gas, and the products resulting from the reaction can be removed separately via the channels and fed to an analysis unit. The recesses for receiving the solids are preferably arranged in the form of a matrix.

Description

The The invention relates to a method for testing the catalytic activity of a Reactive gas exposed solids with a unit for receiving the solids and a unit of analysis of the reaction resulting products.

to The preparation and characterization of catalysts are potentially active carrier and Catalyst components combined in supposedly suitable manner and the multicomponent mixtures thus created with a suitable test reaction under certain, mostly technical limitations Conditions tested. While the synthesis of such materials often still with time-manageable Effort to be handled On the other hand, the testing of the catalysts is very time-consuming and labor-intensive step In general, the material to be tested in a specially therefor designed laboratory test reactor filled and under predetermined Parameters for its suitability for the respective implementation of a Educt mixture tested.

The EP 0 423 294 B1 describes a device for the investigation and evaluation of fluidized bed cracking catalysts which has a single tubular reactor. The known device is used to perform a series of continuous cyclic experiments while varying experimental conditions.

The WO 97/32208 describes in the embodiment 23 a ceramic monolith with channels that the monolith on its entire length pull through vertically, and which are coated with catalysts. The channels are traversed with reaction gas. An arrangement of sniffing pipes is used to the gas streams by gas chromatography or to be analyzed by mass spectrometry.

Furthermore is the simultaneous testing of catalysts in several separate Reactors known that supplies of a common gas treatment become. Also in the testing of catalysts in parallel reactors is the charging of the catalysts with the materials to be tested a time-consuming and labor-intensive measure. Another disadvantage is that the Number of available standing reactors, which can be operated in parallel, in the Practice is limited.

A crucial innovation of recent years in the bio-organic Synthesis was the development of combinatorial synthetic methods (Furka, A., Sebastién, F., Asgedom, M., Dibo, G., Abstr. 14th Int. Congr. Biochem., Prague 1988, Vol. 5, 47). Most of time is used in such syntheses only with very small amounts of substance and often become polymeric carriers for fixing one of the reactants and the resulting products used. Thus, the combinatorial synthesis today one the standard tools in the bio-organic Chemistry. The efficient testing of a substance library, the produced by such synthetic methods is currently in the so-called "high throughput screening " most advanced testing of potential pharmaceuticals Service. Current test methods are based on the addition of the substance from the substance database to an enzyme or Cell cultures that determine the presence of an interaction between the substance and a specific active site in the enzyme or in the cell metabolism indicate by a luminescence. Substances from libraries are in so-called "arrays", under which plates with depressions, which serve as reaction vessels, are to be understood, contacted with the respective test system, then done often a suitable further treatment of the sample (irradiation, Incubation, etc.), followed by the final assessment test.

The first approaches a transmission Combinatorial synthesis and testing of inorganic solids were 1995 by Schultz et al. released (Xiang, X.-D., Sun, X., Briceno, G., Lou, Y., Wang, K.A., Chang, H., Wallace-Freedman, W. -G., Chen, S. -W., Schultz, P.G., Science 268, 1995, 1738 and Briceno, G., Chang, H., Sun, X., Schultz, P.G., Xiang, X.D., Science 270, 1995, 273 and Sun, X.D., Wang, K. -A., Yoo, Y., Wallace-Freedman, W.G., Gao, C., Xiang, X. -D., Schultz, P.G., Adv. Mater. 9, no. 13, 1997, 1046 and Wei, T., Wallace-Freedman, W.G., Schultz, P.G., Xiang, X. -D., Appl. Phys. Lett. 68, 1996, 3506). Here, a coating method is used to prepare the compound used that by masking techniques the production of various Combinations allowed on a substrate.

Of the decisive disadvantage of Schultz et al. described method The first is that through the coating process is only a very small part of the chemical potential Combination is made, which are conventional with conventional in the catalyst preparation Wet chemical method can be obtained. Thus the library becomes the possible one catalytically active candidate considerably reduced. A procedure to test the catalytic activity of the materials is not described.

In the field of simultaneous testing of catalysts, a work by Luss et. al. (Moates, FC, Somani, M., Annamalai, J., Richardson, JT, Luss, D., Willson, RC, Ind. Eng. Chem. Res. 35, 1996, 4801) in which catalyst pellets were tested by infrared thermography. However, this method is limited to reactions with high heat of reaction. Selectivity differences are not detected.

Of the Invention has for its object to provide a method with which the catalytic activity is exposed to a reaction gas Solids without major time and workload can be tested effectively.

The solution This object is achieved according to the invention with the features of the claim 1.

The inventive method allows the simultaneous but also sequential testing of a large number of solid state catalysts, which are exposed to a reaction gas, the conditions such Pressure, temperature, etc. can be freely varied.

The in the process according to the invention used arrangement comprises a receiving unit having a plurality of recesses for receiving each a solid having tested its catalytic activity shall be. about a common gas supply will be all solids in the receiving unit exposed to the reaction gas simultaneously. The gas flow is in the individual recesses assigned to channels, so that the over each Catalyst resulting products separately for each solid in the analysis unit can be analyzed. The analysis can be carried out, for example, by the known spectroscopic, carried out by spectrometric or chromatographic methods. During the Test phase can only unlock one of the channels to the analysis unit be while the above the other channels dissipated Gas is not analyzed. The recording unit allows but also the analysis of over several channels dissipated Gas flow. It can also any number of channels be closed so that they does not flow through the reaction gas become.

In a preferred embodiment the receiving unit, the recesses are arranged in the form of a matrix. The arrangement in the form of a matrix not only allows the testing a big one Number of catalysts in a small space, but also facilitates the introduction of the solids to be tested in the recesses by means a feed unit in which the catalysts are synthesized and then transferred to the recesses of the receiving unit. But it is also possible to synthesize the catalysts directly in the receiving unit.

The channels for discharging the gas stream are preferably located at the bottom of the recesses, So that the Catalysts are flowed through by the reaction gas.

The Feeding unit for the simultaneous introduction of the substances in the receiving unit has the individual recesses associated Channels on, in which the catalysts are spatially separated by combinatorial methods can be produced. To the channels to close the feed unit to synthesize the solids is advantageously provided a slide, all channels closes or releases.

The channels the loading unit are corresponding to the recesses of the receiving unit arranged. To transfer the Solids the feed unit is attached to the receiving unit, the channels the feed unit then aligned with the recesses of the receiving unit.

To the Squeezing the solids from the recesses comprises the arrangement according to the invention advantageously a pressing tool, that the channels having the loading unit associated with ram.

to Adjustment features the recording unit over a circumferential approach in which the feed unit fits can be used. When the loading unit is removed set a lid on the peripheral approach of the receiving unit, so that one common gas supply chamber for the recesses is created in the receiving unit. By a Bore in the lid, the reaction gas then the common gas supply chamber supplied become.

In a further preferred embodiment the receiving unit has a heater to the desired reaction temperature to be able to adjust.

The sit to be tested solid state catalysts preferably on platelets made of porous Material in the recesses of the receiving unit transverse to the flow direction of the reaction gas are arranged.

in the The following will be an embodiment of inventive arrangement for testing the catalytic activity of a reaction gas exposed Solids, with reference to the drawings explained in more detail.

It demonstrate:

1 the receiving unit of the arrangement for testing the catalytic activity of solids exposed to a reaction gas in a sectional representation,

2 a section through the receiving unit along the line II-II of 1 .

3 the recording unit of 1 in the plan view,

4 the gas flow scheme of the test arrangement,

5 the loading unit of the test arrangement in a sectional representation,

6 a section through the feed unit along the line VI-VI of 5 .

7 the slider of the loading unit of 5 in the plan view,

8th the pressing tool of the test arrangement in a sectional view and

9 the crushing unit of the test arrangement in a sectional view.

The assembly for testing the catalytic activity of solids comprises a receiving unit 1 ( 1 to 3 ), in which the solid-state catalysts are exposed to a reaction gas, an analysis unit 2 with a valve assembly 3 ( 4 ) which analyzes the products resulting from the reaction and a feed unit 4 with a pressing tool 5 in which the catalysts are prepared spatially separated by combinatorial methods ( 5 to 8th ).

1 shows a section through the receiving unit 1 the test arrangement. The recording unit 1 has a cylindrical body 6 made of thermally conductive material, preferably brass, which on its upper side with cylindrical bores 7 arranged in the form of an n × m matrix with four rows and four columns ( 2 ). A 4 × 4 matrix is given by way of example only, arrangements with a much larger number of recesses are possible.

At the bottom of each recess 7 is a channel 8th connected to the bottom of the brass body 6 from the receiving unit 1 out leads. The channels 8th run parallel to each other in the vertical direction. They have a smaller diameter than the recesses. This ensures similar flows through all the recesses since the channels represent the respective main flow resistances. The individual channels can also be selectively narrowed in order to set exactly the same flows in all recesses. For this purpose, corresponding throttling devices or the like can be provided in the receiving unit.

At the top of the brass body 6 is a flange 9 for fixing a lid 10 made of thermally conductive material, preferably brass, attached. flange 9 and lid 10 have a plurality of circumferentially distributed holes arranged 11 on, so that the cover can be firmly screwed to the brass body ( 3 ). For sealing the lid 10 opposite the flange 9 is a ring seal 12 provided in an annular groove 13 of the flange 9 sitting.

The brass body 6 and the lid 10 have holes 14 for holding heating cartridges 15 a heater on to the receiving unit 1 to heat up to the reaction temperature.

The catalysts to be examined each sit on a small plate 16 of a porous innermost mass (frit) disposed at the bottom of each recess transverse to its longitudinal axis.

For simultaneous testing of the catalysts is the lid 10 with the flange 9 of the brass body 6 screwed and provided in the lid holes 17 . 18 the reaction gas is in the above the recesses 7 located gas supply chamber 19 directed. The reaction gas flows through the on the frits 16 sitting catalysts 20 and is over the channels 8th dissipated.

4 shows the Gasflußschema the test arrangement. The reaction gas flows out of a gas container 21 via a gas supply line 22 into which a metering device 23 is switched, in the recesses 7 that of the temperature control unit 42 heated to the reaction temperature recording unit 1 , so that the catalysts are flowed through by the reaction gas.

The products resulting from the reaction become separate for each catalyst over the separate channels 8th discharged separately to the effluent selectively to the analysis unit 2 to be able to supply.

At the outlet of each channel 8th is the inlet of a multiport valve 24 connected. The multiport valves are electromagnetically actuated and are controlled by a control unit 25 via control lines 26 driven. The first output of each multiport valve 24 is over a gas pipe 27 with a first common gas discharge line 28 connected to the analysis unit 2 leads while the second output of each multiport valve 24 via a second gas line 29 with a second common gas discharge line 30 connected to the analysis unit 2 , eg a mass spectrometer.

Depending on the switching position of the multiport valves, the products resulting from the reaction for each catalyst can be separated one after the other from the analysis unit 2 or the effluent from any two catalysts can be analyzed. The valve arrangement consisting of the multiport valves can be expanded as required depending on the number of catalysts to be tested.

Instead of a valve arrangement for unlocking the individual channels can also below the receiving unit 1 a manipulator may be arranged with an inlet capillary movable in the xyz direction, to which the analysis unit is connected. The inlet capillary can then be retracted successively in the channels with the manipulator so that the effluent of each catalyst can be analyzed separately. In principle, however, each channel can be assigned a separate analyzer, so that a higher parallelized analysis is possible.

5 shows a section through the loading unit 4 the test arrangement. The loading unit 4 has a two-part cylindrical metal body 31 on, whose diameter is the inner diameter of the flange 9 the recording unit 1 corresponds, so that the loading unit 4 in the receiving unit 1 can be used appropriately. The cylindrical metal body 31 has channels arranged in the form of a 4 × 4 matrix 32 on. The arrangement and the diameter of the channels 32 corresponds to the recesses 7 the recording unit 1 so that they are aligned when the loading unit is inserted into the receiving unit.

Between the upper and lower part 31a . 31b of the cylindrical metal body is a slider 33 transverse to the longitudinal axis of the channels 32 slidably guided. The slider 33 is a sheet metal plate with holes 34 , which are also arranged in the form of a 4 × 4 matrix. These holes 34 aligned with the channels 32 of the cylindrical metal body 31 , The two fasteners 35 , which hold the upper and lower part together, extend through lateral slots 36 of the slider 33 and limit its sliding path. The slider 33 can be moved between two positions, in which the channels 32 the loading unit are closed or released.

The slider 33 is preferably made of metal. But it is also possible that the slide is a perforated plate of porous material (frit), which is used for filtration when the slide is in a position in which the holes of the perforated plate are not aligned with the channels of the feed unit.

6 shows a section through the pressing tool 5 the test arrangement. The test tool has in the form of a 4 × 4 matrix arranged press punches 37 on that with screws 38 on a round plate 39 are attached. The punches 37 are arranged and dimensioned so that they open slider 33 fitting in the channels 32 the loading unit 4 can be inserted.

7 shows a section through a crushing unit 40 in the form of a lattice, consisting of cutters arranged at right angles at a distance of about 2 mm 41 consists. The shredding unit 40 can in the gas supply chamber 19 the recording unit 1 be inserted before the loading unit 4 is used in the receiving unit to comminute the prepared in the feed unit solids during transfer into the receiving unit. However, the comminution unit may also be integral with the feed unit.

following is a carbon monoxide oxidation of combinatorial produced Catalysts described using the above test arrangement.

For this Test reaction were combinatorially prepared catalysts the bearers Zcolith Y, alumina, titania and zirconia in combination with the potentially catalytically active metals platinum and palladium and the promoter cerium for the test reaction of the catalytic oxidation of carbon monoxide too Tested carbon dioxide. Here, the catalysts were a reaction gas mixture exposed to synthetic air and 80 carbon monoxide. The temperature the reaction gas atmosphere was heated gradually and thereby the product gas flow in the individual channels for the respective Reaction gas temperature analyzed spectroscopically.

The catalysts are synthesized in the top of the cylindrical body of the feed unit with the slide closed. In this case, in each of the four columns another carrier material is deposited, eg in column 1 a silicate carrier, in column 2 an alumina, in column 3 a titanium dioxide and in column 4 a zirconium oxide. The catalytically active substance is then applied, for example, by an impregnation impregnation method, eg in line 1 a certain volume of a platinum salt solution, in line 2 a certain volume of a palladium salt solution, in line 3 a certain volume of a platinum salt and a palladium salt solution and in line 4 a certain volume of a platinum salt, a palladium salt and a cerium salt solution. By a suitable high temperature treatment, the solvent is removed. This is followed by a post-treatment, for example with hydrogen. In order to be able to transfer the sample array into the receiving unit, the comminution unit is inserted into the gas supply chamber of the feed unit and the feed unit is inserted into the receiving unit. When the slide is open, the solid state catalysts are then pressed by means of the pressing tool from the channels of the feed unit through the grid-like plate in the recesses of the receiving unit. If comminution of the solids prepared in the feed unit is not required, the insertion of the comminution unit into the receiving unit can also be dispensed with. Then the shredding unit and the loading unit are again removed from the receiving unit. Subsequently, the receiving unit is sealed with the lid and the reaction gas is supplied. Now, the product gas stream discharged from the catalysts via the individual channels of the receiving unit is spectroscopically analyzed in the analysis unit, while the temperature of the reaction gas atmosphere is increased stepwise.

Claims (5)

Method for testing the catalytic activity of a Reaction gas exposed solids using a device full • one Unit for receiving the solids, • and a unit for analysis the products resulting from the reaction, where the unit for recording has: • several Recesses for receiving a respective solid, • a common Gas supply • one heater • such as at the individual recesses connected channels with a diameter of the smaller than the diameter of the recesses the Procedure so led will that (I) all solids are simultaneously exposed to the reaction gas, (Ii) the resulting products in the reaction via the channels separated and discharged fed to the analysis unit become; (iii) the channels represent the respective main flow resistances and similar rivers be ensured by all recesses. Method according to claim 1, characterized in that that the individual channels narrowed targeted. Method according to claim 1 or 2, characterized that the products resulting from the reaction are for everyone Catalyst over the separate channels discharged separately to selectively supply the effluent to the analyzer can. Method according to one of claims 1 to 3, characterized that an inlet capillary with a manipulator is sequentially inserted into the channels, so that the effluent of each catalyst can be analyzed separately. Method according to one of claims 1 to 4, characterized that the catalysts are synthesized directly in the unit for uptake become.