Engineering CuOx-ZrO2-CeO2 nanocatalysts with abundant surface Cu species and oxygen vacancies toward high catalytic performance in CO oxidation and 4-nitrophenol reduction
Surface highly dispersed Cu species and oxygen vacancies are important for the CuOx-CeO2 catalysts in many reactions, but it is difficult to increase simultaneously the concentrations of highly dispersed Cu species and oxygen vacancies only by adding Cu component. Herein, CeO2-ZrO2-CuOx (CZC) nanocatalysts with different ratios of Cu/Zr have been effectively produced by a simple solvent-free synthetic strategy. The effect of Zr doping on the structure and reactivity of CuOx-CeO2 catalysts has been investigated with the help of carbon monoxide (CO) oxidation and 4-nitrophenol (4-NP) reduction as model reactions. It is revealed that the introduction of Zr relieved the agglomeration of surface Cu species, produced more oxygen vacancies in interior and Cu+ species on the surface of the catalyst, increased the reducibility of CuOx-CeO2. CZC catalysts show remarkably enhanced catalytic activity due to the abundant surface active sites and the improved redox property provided by suitable doping of Zr into CuOx-CeO2. This work not only testifies a practicable way to reconstruct the distribution of active metals on metal oxides support but also provides a high-efficiency strategy to prepare oxides catalysts with excellent catalytic performance.