Interplay between Molybdenum Dopant and Oxygen Vacancies in a TiO2 Support Enhances the Oxygen Reduction Reaction

In this study, molybdenum doping of anatase TiO2, used as a Pt catalyst support, both augments resistance against the carbon corrosion that commonly occurs in oxygen reduction reaction (ORR) Pt/C catalysts and promotes the generation of oxygen vacancies that allow better electron transfer from the nanosupport to Pt, thereby facilitating the oxygen dissociation reaction. The effects of the oxygen vacancies within the Mo-doped TiO2 nanosupport on ORR activity and stability are investigated both experimentally and by density functional theory analysis. The mass activity of Pt supported molybdenum-doped anatase TiO2 is shown to be 9.1 times higher than that of a commercial standard Pt/C catalyst after hydrogen reduction. The oxide-supported nanocatalysts also show improved stability against Pt sintering under during cycling, because of strong metal support interactions.