New insight of the Mars-van Krevelen mechanism of the CO oxidation by gold catalyst on the ZnO(1 0 1) surface

Abstract

We performed theoretical studies of the Mars-van Krevelen (M-vK) mechanism of the CO oxidation by gold catalyst supported on ZnO(101) surface. The activities of the lattice oxygen at the Au/ZnO interface are related with its coordination and orientation. The 3-coordinated O3c″ shows the highest activity because of the feasible achievement of the analogous single-atom catalytic active site of Au/CeO2. However, the CO2 desorption does not determine the kinetics of CO oxidation for Au/ZnO that is different from the case of Au/CeO2. Thus, the M-vK reactivity of CO oxidation cannot be measured by the vacancy formation energy of the lattice oxygen of Au/ZnO. Rather, the high reactivity is found closely related with the large interfacial AuAu bond distortion in the transition states, which can be used to depict the M-vK reactivity of the CO oxidation on Au/ZnO.