CuO/CeO2 catalysts synthesized from Ce-UiO-66 metal-organic framework for preferential CO oxidation

We synthesized a CuO/CeO2 catalyst using a copper ions encapsulated ceria metal-organic framework (MOF) Ce-UiO-66 as the precursor. The CuO/CeO2 catalysts derived by calcining the MOF precursor (the x-CuCe catalysts) showed the better activity and selectivity for the preferential CO oxidation in the H2-rich stream than the CuO/CeO2 catalyst prepared by wetness impregnation (CuCe-im). A temperature window to match the CO conversion and O2 to CO2 selectivity higher than 99.5% at the same time appeared using the x-CuCe catalysts as the catalyst. Raman and XPS results indicated that more oxygen vacancies were formed in the bulk of ceria in the x-CuCe catalysts than that in the CuCe-im catalyst, which could promote the mobility of oxygen. Our results indicated that the surface lattice oxygen and the oxygen vacancies in the bulk of ceria could enhance the catalytic performance of the CuO/CeO2 catalysts.