Unraveling the Change in Multiple Cu Species Present in CuO/CeO2 over the Preferential CO Oxidation Reaction

CuO/CeO2 with strong metal-support interaction was considered to be a highly efficient catalyst in the PROX (preferential CO oxidation reaction. Multiple Cu species from this interaction were believed to play a key role in catalytic activity. However, due to the complex chemical properties of copper, there was still controversy about the nature of active sites in the PROX reaction. In this work, the types and proportion of Cu species (Cu-[O](x)-Ce, amorphous CuOx and aggregated CuOx) could be well-controlled since CuO was loaded on surface-modified CeOx. Their properties were studied in detail through a series of characterizations. The Cu-[O](x)-Ce structure was found to be the most favorable for preferential CO oxidation. While the amorphous CuOx cluster could facilitate CO oxidation, it would greatly reduce the selectivity. The aggregated CuOx caused by excessive CuO only had activity at high temperature, resulting in an upper limit of the CuO loading amount. The proportion of these Cu species varied with the CuO loading amount, and the catalytic performance was the synergetic result of all Cu species.

Automated summary

CuO/CeO2 with strong metal-support interaction is considered as an efficient catalyst for the preferential CO oxidation reaction (PROX). Different Cu species in this catalyst, including Cu-[O](x)-Ce structure, amorphous CuOx, and aggregated CuOx, affect the catalytic activity differently. The proportion of these Cu species varies with the CuO loading amount, and their synergistic effects determine the overall catalytic performance.