Water-Mediated Mars–Van Krevelen Mechanism for CO Oxidation on Ceria-Supported Single-Atom Pt1 Catalyst

In water-promoted CO oxidation, water was thought not to directly participate in CO2 production. Here we report that via a water-mediated Mars–van Krevelen (MvK) mechanism, water can directly contribute to about 50% of CO2 production on a single-atom Pt1/CeO2 catalyst. The origin is the facile reaction of CO with the hydroxyl from dissociated water to yield the carboxyl intermediate, which dehydrogenates subsequently with the help of a lattice hydroxyl to generate CO2 and water. The water-mediated MvK type reaction found here provides new insights in the promotion role of water in heterogeneous catalysis.