Kinetic and Computational Studies of CO Oxidation and PROX on Cu/CeO 2 Nanospheres

As supported CuO is well-known for low temperature activity, CuO/CeO 2 nanosphere catalysts were synthesized and tested for CO oxidation and preferential oxidation of CO (PROX) in excess H 2 . For the first reaction, ignition was observed at 95 °C, whereas selective PROX occurred in a temperature window from 50 to 100 °C. The catalytic performance was independent of the initial oxidation state of the catalyst (CuO vs. Cu 0 ), suggesting that the same active phase is formed under reaction conditions. Density functional modeling was applied to elucidate the intermediate steps of CO oxidation, as well as those of the comparably less feasible H 2 transformation. In the simulations, various Cu and vacancy sites were probed as reactive centers enabling specific pathways.