Low Temperature Selective CO Oxidation in Excess of H2 over Pt/Ce—ZrO2 Catalysts

Pt/Ce—ZrO2 catalysts have been designed and applied to selective CO oxidation at low temperature. Both tetragonal and cubic phase Ce—ZrO2 supports were prepared by co-precipitation method to get high surface area materials after calcination at 500 °C for 6 h in air. Selective CO oxidation was conducted using stoichiometric amounts of O2. Cubic Ce—ZrO2 supported Pt catalyst exhibited 78% CO conversion and 96% CO2 selectivity even at 60 °C, while Pt/Al2O3 catalyst showed less than l% CO conversion at the same condition. The higher CO conversion and CO2 selectivity (to CO2 as opposed to H2O) of Pt/Ce—ZrO2 catalyst is mainly due to the high oxygen storage capacity of Ce—ZrO2 and nano-crystalline nature of cubic Ce0.8Zr0.2O2.