Highly dispersed Ag nanoparticles embedded on the surface of CeO2/CF nanowires derived from three-dimensional structured Cu foam for toluene catalytic oxidation

Abstract

A novel catalyst with special three-dimensional structure was prepared for the catalytic oxidation of toluene using a three-step electrochemical process, in which copper nanowires (CNWs) were generated on the surface of three-dimensional Cu foam (CF) by an electro-oxidization process at first and then, CeO2 was uniformly coated on the CNWs by a unipolar pulse electro-deposition (UPED) method and finally highly dispersed Ag nanoparticles were embedded on the surface of CeO2 using a constant voltage electrodeposition method. It is found that the suitable Ag loading amount effectively enhanced the low-temperature reducibility, the generation of oxygen vacancies, and distribution of surface acid sites, which are favorable to the catalytic oxidation of toluene. Especially, the obtained 80Ag-CeO2@CNWs/CF catalyst with an electrodeposition time of 80 s for Ag loading exhibited the best catalytic activity with the T10, T50 and T90 of toluene conversion at 222, 240 and 256 °C, respectively. Long-term stability tests with and without water vapor further indicated that the 80Ag-CeO2@CNWs/CF catalyst had good stability and water resistance ability during the catalytic oxidation of toluene. It is expected that the present electrodeposition method could be a promising way to prepare high-performance catalysts for the catalytic oxidation of VOCs.