Co3O4 Nanosheet/Au Nanoparticle/CeO2 Nanorod Composites as Catalysts for CO Oxidation at Room Temperature

CO oxidation at room temperature has become a hot research topic due to its scientific and environmental applications, and nanoscale catalysts are considered to be a bridge to this goal. In this study, a three-dimensional (3D) porous nanosheet/nanorod woven Au/Co3O4-CeO2 catalyst with a large specific surface area was prepared by dealloying AI-Ce-Co-Au precursor alloy ribbons combined with calcination. The experimental results revealed that the Au nanoparticles were loaded on both Co3O4 nanosheets and CeO2 nanorods. The optimized Au/Co3O4-CeO2 catalyst can completely convert CO at near room temperature (30 degrees C) under a high space velocity (60 000 h(-1)), exhibiting a significant improvement compared to Au/CeO2, and the catalytic activity does not exhibit any decrease tendency even after 125 h of continuous performance in feed gas with a very high vapor concentration (5 x 10(4) to 2 x 10(5) ppm), which implied the extreme stability and water vapor resistance of the catalyst. Systematic characterizations revealed that the improvements in catalytic activity can be attributed to the small amount of nanoscale Co3O4 added, which significantly increased the oxygen vacancies and surface active oxygen species in the sample. Moreover, the rough interfaces formed by the interweaving of nanosheets and nanorods also enhanced the strong metal-support interactions, thereby increasing the concentration of more active Au delta+ species. In addition, the process of CO catalytic oxidation on samples and the CO oxidation mechanism under anaerobic conditions were investigated by in situ diffuse reflection infrared Fourier transform spectroscopy (DRIFTS), paving a feasible pathway for the rational design of high-performance nanoscale catalysts.