Insight into the high efficiency of Cu/CeO2(1 1 0) catalysts for preferential oxidation of CO from hydrogen rich fuel

Abstract Ceria nanosheets with predominantly exposing {1 1 0} planes had been synthesized, and used as supports to prepare copper-based catalysts for preferential oxidation of CO from hydrogen rich fuel (PROX). The 3 wt% CuO/CeO2(1 1 0) catalyst shows excellent catalytic performance, achieving Con. 100% and Sel. 99.8% at 90 °C after a pretreatment with the reaction gas. Quasi in-situ XPS and HS-LEIS results, as well as CO-DRIFTS, reveal that the relative ratio and dispersion of Cu+ on the surface increase after treating with the reaction gas. These results disclose that the interface between Cu+ and CeO2 should play main roles for CO oxidation. The obtained apparent activation energy for hydrogen oxidation is much higher than that for CO oxidation. The selectivity for H2 oxidation increases significantly and Cu0 appears concurrently at a higher reaction temperature, leading that Cu0 is more favor for H2 oxidation. Therefore, to stabilize Cu+ on CeO2 is the key to achieve high catalytic performance for PROX.