High-throughput synthesis and screening of catalytic materials - Case study on the search for a low-temperature catalyst for the oxidation of low-concentration propane

Low-temperature catalysts for the total combustion of low-concentration pro pane in air have been searched for applying a combinatorial approach includ ing an optimization procedure based on a genetic algorithm. A ist generatio n of catalysts was prepared by impregnation of TiO2 and Fe2O3 materials wit h randomly mixed solutions of eight individual compounds (H-2[PtCl6]. xH(2) O, (NH4)(2)PdCl6, RhCl3. 2H(2)O, RuCl3.H2O, H[AuCl4]. 3H(2)O, Ag lactate, C u(NO3)(2), Mn(NO3)(2)) considered as potential catalytic compounds. After p arallel testing of the Ist generation of the catalytic materials applying h igh-throughput testing equipment the most active catalysts were chosen to c reate a 2nd and after its testing a 3rd generation, respectively. A genetic algorithm was applied to set the compositions of the catalytic compounds o f the 2nd and 3rd generation. Fe2O3 was not used as support for the succeed ing generations since it lead to significantly inferior catalytic performan ces than TiO2. The optimization strategy led to improved catalysts. Most of the final material converted propane to CO2 at 150 degreesC, the best ones oxidized propane even at 50 degreesC. Furthermore, the goal was pursued to compare the performance of two differe nt high-throughput testing equipments. In both cases the ranking of 45 cata lysts was nearly the same. (C) 2001 Elsevier Science B.V. All rights reserv ed.