Defect engineering by steam treatment over Pt/CeO2 catalyst promoting C–H activation in partial oxidation of methane

Reducible oxides such as ceria have been certified to significantly enhance the catalytic activity of redox reactions. In this study, Pt/CeO2 catalyst was treated with steam, a good deal of hydroxyl groups came into being on surface to form Pt–OH species, thus achieving a high degree of Pt dispersion. The results of O2-TPD, XPS, Raman and EPR indicated that the dissociation of steam at surface vacancy was in favor of activation and removal of lattice oxygen and generation of oxygen vacancies. DFT calculation and in situ DRIFTS results showed that the oxygen vacancy was favorable for activating C–H bond in methane. The Pt/CeO2–H2O catalyst with abundant oxygen vacancies presented outstanding catalytic activity than that of Pt/CeO2, the CH4 conversion rate, CO and H2 selectivity was 62%, 60% and 58%, respectively. What's more, defective engineering promoting methane partial oxidation can be extended to all kinds of redox reactions.