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High-throughput and combinatorial approaches have been applied to the discovery of catalysts for selective low temperature CO oxidation/VOC removal using mixed CO/propylene feeds, and for the water-gas shift (WGS) reaction using real post-reformer feeds containing CO, CO 2 , H 2 O and H 2 . The screening approach was based on a hierarchy of qualitative and semi-quantitative primary screens for the discovery of hits, and quantitative secondary screens for hit confirmation, lead optimization and scale-up. For WGS, primary screening was carried out using scanning mass spectrometry. For CO oxidation and VOC removal, parallel IR thermography was the primary screen. Multi-channel fixed bed reactors equipped with imaging reflection FTIR spectroscopy or GC were used for secondary screening. Novel RuCoCe compositions were discovered and optimized for CO oxidation/VOC removal and the effect of doping was investigated for supported and bulk mixed oxide catalysts. For WGS, noble metal-free and Pt-doped CoFeRu mixed oxides as well as Pt on CeO 2 and Pt on CeO 2 /ZrO 2 were investigated and a new synergistic PtFeCe ternary composition was discovered. In these cases oxygen vacancies in the ceria lattice are believed to play a key role in the strong and synergistic Pt-Ce interaction. Alkaline metal doping was found to enhance the selectivity towards WGS by suppressing the unselective methanation side reaction and to increase the low temperature catalytic activity.

The catalytic oxidation of carbon monoxide to carbon dioxide is an important process used in several areas such as respiratory protection, industrial air purification, automotive emissions control, CO clean-up of flue gases and fuel cells. Research in this area has mainly focused on the improvement of catalytic activity at low temperatures. Numerous catalyst systems have been proposed, including those based on Pt, Pd, Rh, Ru, Au, Ag, and Cu, supported on refractory or reducible carriers or dispersed in perovskites. Well known commercial catalyst formulations for room temperature CO oxidation are based on CuMn2O4 (hopcalite) and CuCoAgMnOx mixed oxides. We have applied high-throughput and combinatorial methodologies to the discovery of more efficient catalysts for low temperature CO oxidation. The screening approach was based on a hierarchy of qualitative and semi-quantitative primary screens for the discovery of hits, and quantitative secondary screens for hit confirmation, lead optimization and scale-up. Parallel IR thermography was the primary screen, allowing one wafer-formatted library of 256 catalysts to be screened in approximately 1 hour. Multi-channel fixed bed reactors equipped with imaging reflection FTIR spectroscopy or GC were used for secondary screening. Novel RuCoCe compositions were discovered and optimized for CO oxidation and the effect of doping was investigated for supported and bulk mixed oxide catalysts. Another family of active hits that compare favorably with the Pt/Al2O3 benchmark is based on RuSn, where Sn can be used as a dopant (e.g. RuSn/SiO2) and/or as a high surface area carrier (e.g., SnO2 or Sn containing mixed metal oxides). Also, RuCu binary compositions were found to be active after a reduction pretreatment with hydrogen.

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