Insight into the Ag-CeO2 interface and mechanism of catalytic oxidation of formaldehyde

Abstract

The interfacial effects between noble metals and supports should be well understood for the design of efficient and low-cost catalysts for HCHO removal. Two Ag/CeO2 catalysts were prepared by using two CeO2 supports with well-defined crystal planes: a nanorod enclosed with the {110} and {100} crystal planes (Ag/CeO2-rod) and commercial CeO2 enclosed with the {111} crystal plane. The reactivity results demonstrated that Ag/CeO2-rod was a highly efficient active catalyst, which completely oxidized HCHO at 80 ℃. Compared to commercial CeO2, CeO2 nanorod had more oxygen vacancies and surface-active oxygen species, which were further promoted by the Ag-CeO2 interface. The HCHO could be quickly adsorbed and oxidized at the Ag-CeO2 interface, which led to the high reactivity for HCHO oxidation. This article not only proposes the reaction mechanism of HCHO oxidation but also provides ideas for the design of additional highly efficient and low-cost catalysts.