Hollow copper-ceria microspheres with single and multiple shells for preferential CO oxidation
The architecture of catalyst particles plays an important role in determining the catalytic properties. However, the challenge is the ability to tune the architecture at nanoscale. Herein we report the design and construction of hollow CuO/CeO2 microspheres with controllable shells, which exhibit significantly enhanced catalytic performance. The hollow CuO/CeO2 microspheres with single and multiple shells were synthesized by self-templating method. The catalytic activity of the catalysts for preferential CO oxidation is shown to increase with increasing the number of the spherical shells. A maximized performance is observed for the triple-shelled catalyst, reaching CO conversion of 100% and CO2 selectivity of 91% at 95 oC. The triple-shelled catalyst also displays a broad temperature window for CO total conversion from 95 oC to 195 oC. The findings are attributed to the enhanced exposure of the active sites on the surface of the triple-shelled architecture, fine-tunable geometric and electronic interaction, and increased space inside the catalyst, which together amplify the reactant access and interaction.