Enhancing CO Preferential Oxidation in H₂-Rich Stream on Solid Solution CuO_CeO₂ Catalyst with Abundant Oxygen Vacancies

In this study, we propose a strategy for preparing solid solution CuO_CeO₂ 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 CeO₂ lattice. Notably, 99.5% CO conversion and 58.2% CO₂ selectivity are achieved at a WHSV of 36,000 mL/(h·g_cat) with only 4.41 wt % Cu loading. No decrease in efficiency is observed within 150 h. DFT calculations reveal that the O₂ is favorably adsorbed and activated at oxygen vacancies of Cu-Ce-V_[O], 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.