Enhancing CO Preferential Oxidation in H-Rich Stream on Solid Solution CuO_CeO Catalyst with Abundant Oxygen Vacancies.

In this study, we propose a strategy for preparing solid solution CuO_CeO catalysts derived from Ce-based MOFs for CO preferential oxidation. The support provided by frameworks and the anchoring of amino groups prevent the agglomeration of Cu species during subsequent annealing. Therefore, highly dispersed Cu species are formed, and even some are atomically embedded in the CeO lattice. Notably, 99.5% CO conversion and 58.2% CO selectivity are achieved at a WHSV of 36,000 mL/(h·g) with only 4.41 wt % Cu loading. No decrease in efficiency is observed within 150 h. DFT calculations reveal that the O is favorably adsorbed and activated at oxygen vacancies of Cu-Ce-V, whereas the CO adsorption is localized at Cu ion sites. Highly dispersed Cu species and neighboring oxygen vacancies provide abundant active sites for CO oxidation via the noncompetitive L-H mechanism. This research offers insights for designing efficient non-noble metal catalysts and understanding the reaction mechanism.