Insight into the high efficiency of Cu/CeO2 (110) catalysts for preferential oxidation of CO from hydrogen rich fuel

Ceria nanosheets with predominantly exposing {110} 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 (110) catalyst shows excellent catalytic performance, achieving Con. 100% and Sel. 99.8% at 90 degrees 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 H-2 oxidation increases significantly and Cu-0 appears concurrently at a higher reaction temperature, leading that Cu-0 is more favor for H-2 oxidation. Therefore, to stabilize Cu+ on CeO2 is the key to achieve high catalytic performance for PROX.