Hollow copper–ceria microspheres with single and multiple shells for preferential CO oxidation

Abstract

The architecture of catalyst particles plays an important role in determining the catalytic properties. However, the challenge is the ability to tune the architecture on a 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 a 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 maximum performance is observed for the triple-shelled catalyst, reaching a CO conversion of 100% and CO₂ selectivity of 91% at 95 °C. The triple-shelled catalyst also displays a broad temperature window for CO total conversion from 95 °C to 195 °C. 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 interactions, and increased space inside the catalyst, which together amplify the reactant access and interaction.