Highly selective CO methanation catalysts for the purification of hydrogen-rich gas mixtures

High-throughput techniques based on emissivity-corrected infrared thermography (ecIRT) were used in the discovery and optimization of new catalysts for the purification of hydrogen-rich gas reformates by means of CO methanation. The application of an appropriate sequence of test gases in the high-throughput experiment (HTE) enabled us to screen for activity as well as selectivity. From literature and prescreening of about 2000 samples of highly diverse mixed oxides, we selected suitable elements for more detailed studies in the first, generation. Among these 1000 samples, various doped Ni oxides proved most promising and were selected as leads for the subsequent evolutionary optimization based on selection and variation. Rapid optimization was achieved during three catalyst generations. The improvement in the catalysts in terms of CO activity and selectivity was confirmed at various stages during the developing process by conventional gas-phase experiments. Compared with a typical industrial methanation catalyst (Ru/TiO2), the Re2Y9Ni89Ox and Ti8Hf9Ni83Ox investigated here exhibit unique catalytic performances with respect to activity and selectivity, reducing or eliminating the problems of hydrogen loss by CO2 methanation. Strong evidence for good stability of the best catalysts was obtained by long-term HT screening for about 100 h. Characterization of selected materials is provided. (C) 2007 Elsevier Inc. All rights reserved.