Halloysite-assisted strong binary oxides-support interactions on multisite catalysts for enhanced stability in preferential CO oxidation

Abstract

The inactivation of active sites in thermal catalysis represents an obstacle to the development of promising catalysts for preferential oxidation of CO, in which strong oxide-support interactions play pivotal roles, and it is one of the most efficient approaches for promoting the durability. Herein, the binary oxides-support interactions are modulated to comprehend their effects on the catalyst stability through the dispersion of CuO and CeO2 on the roughened halloysite nanotubes with hydroxyl groups. Detailed experimental studies, in situ spectroscopic characterizations combined with theoretical simulations unveil that the etched surfaces create an abundance of reducible species, and Cu+ can enhance CO affinity on the Cu-Ce-Ox surface and improves the selectivity. More importantly, the catalyst durability is enhanced owing to the strong interactions between oxides and the roughened halloysite nanotubes. A carboxyl pathway is proposed due to the presence of surface-abundant hydroxyl species based on the in situ DRIFTS. The fundamental insights elucidate how to design the stable catalysts with the assistance of supports.