Activation of Oxygen Species on Ag/CoAlO Catalysts to Promote CO Oxidation by Enhancing Metal‐Support Interactions.

Ag catalysts supported on cobalt‐aluminum hydrotalcite derivative (CoAlO) nanosheet for CO oxidation are reported. A facile pre‐reduction treatment on reducible CoAlO support was employed to construct more oxygen vacancies for anchoring Ag sites to tune metal‐support interactions (MSI) and improve metal dispersion. The results show that directly loading Ag on CoAlO (Ag/CoAlO) can significantly promote the generation of active oxygen species by three times. Pre‐reduction of CoAlO enhances MSI of the Ag catalyst (Ag/CoAlO‐R), which further enlarges quantity of active oxygen species. Besides, the kinetic results demonstrate that compared with Ag/CoAlO, Ag/CoAlO‐R shows the additional advantages of the lower activation energy, the higher intrinsic activity of Ag sites, and especially the decreased reaction order of O2 from 0.20 to 0. The latter one indicates that enhancing MSI can readily activate gaseous oxygen at the interface of Ag and CoAlO, and the reaction mechanism obeys a typical Mars‐van Krevelen route. [ABSTRACT FROM AUTHOR]