Screening of a number of heterogeneous catalysts for their selectivities in gas-phase reaction catalysts uses measurements of heats of reaction in reactions with different feed gas compositions

摘要

Screening of heterogeneous gas-phase reaction catalysts regarding their selectivity in certain reactions involves measuring the temperature change of the catalyst as a result of the heat of reaction. This uses a specified process in which the magnitude of the difference of heats of reaction in reactions with different feed gas compositions is used to rank the various selectivities. Testing of a number of heterogeneous gas-phase reaction catalysts as regards their individual selectivities in a certain reaction involves measuring the temperature change of the catalyst as a result of the heat of reaction, the measurement comprising: (1) measuring by IR sensors for the individual catalysts the heat of reaction DELTA T1 in a reaction between 2 gases, especially (a) oxygen and (b) propene; (2) selecting the catalysts with a measurable minimum heat of reaction DELTA T1 min and measuring by IR sensors the heat of reaction DELTA T2 between the product (especially propylene oxide) and one of propylene or oxygen; (3) selecting the catalysts with the lowest heat of reaction DELTA T2 min and conducting a further reaction of one of the reactants (especially oxygen) with a reactant structurally similar to (b) and having only one group competent in the step (1) reaction; and (4) determining the heat of reaction DELTA T3 for this step (3) reaction and selecting those catalysts whose DELTA T3 is very much smaller than DELTA T1.