(560hx) Role of Support Reducibility in the Catalytic Activity of CO Oxidizing Reactions on Pd Loaded Cu-Doped Ceria

Ceria (CeO₂) has been spotlighted as one of the essential components for automobile exhaust-control catalyst due to its facile redoxability or oxygen storage capacity (OSC). In particular, Pd/CeO₂ catalyst has attracted remarkable attention due to the low-temperature CO oxidation activity and the high Pd dispersion owing to strong metal-support interactions (SMSI), which is also important for water-gas shift (WGS) reaction activity at low temperatures.

In this study, Pd-loaded ceria support was doped with Cu to enhance the reducibility. We found that among WGS and CO oxidation reactions, only the activity of WGS reaction was significantly improved on Pd/Cu-doped ceria, indicating that the active oxygen from different source might have been utilized in each reaction. To elucidate this observation, density functional theory (DFT) calculations were performed. The different mechanisms between CO oxidation and WGS on the Pd/Cu-doped ceria catalyst provided the reason why doping the ceria support with Cu resulted in a significant effect on the activity of WGS reaction, not CO oxidation