Development of Highly Selective and Reactive Catalysts for Preferential Oxidation of CO in Reformed Gas -- Activity and Mechanism at Pt-Alloys/Mordenite Catalysts

摘要

Polymer electrolyte fuel cells operating on reformed fuels require CO removal from feed streams to a certain level (e. g. 10 ppm). We have found that Pt, Ru, Pt-Ru and Pt-Fe supported on mordenite oxidize CO much preferentially in H_2-rich gas in comparison with a conventional Pt/Al_2O_3 catalyst. Pt-Fe/mordenite (Pt-Fe/M) exhibited the highest activity and selectivity (ca. 100 percent) for CO oxidation, especially at low temperature below 200 deg C. Such high activity and selectivity for CO oxidation on Pt-Fe/M were not affected by the presence of 25 percent CO_2 and 20 percent H_2O.