(339f) Molybdenum Doped Titanium Oxide As a Novel Support for Enhanced Oxygen Reduction Reaction

The search for catalysts with high activity and longer-term stability for ORR in PEMFC is ongoing. In this research, various amounts of molybdenum were doped into anatase TiO₂ and analysed. The electronic conductivity of Ti_0.9Mo_0.1O_y was significantly improved by doping molybdenum into anatase-TiO₂ structure and hydrogen reduction at 300 ^oC. Later, Pt(111) nanoparticles were reduced and anchored on the thermally treated Ti_0.9Mo_0.1O_y nanosupports (d- Ti_0.9Mo_0.1O_y). The effects of doping and induced oxygen vacancies were investigated both theoretically and experimentally. Rotating disk electrode (RDE) measurements showed that 20 wt% Pt/d- Ti_0.9Mo_0.1O_y catalyst had 1.5 times and ~9.1 times higher Pt mass activity for ORR than those of 10 wt% Pt/d-Ti_0.9Mo_0.1O_y and commercial Pt/C catalysts, respectively. The observed high activity of metal oxide supported-Pt catalyst could be attributed to the role of the advanced oxide support with electron donation from support to Pt catalyst surface, oxygen vacancies on nanosupport surface and high conductivity. Pt nano-electrocatalysts on the advanced robust non-carbon d-Ti_0.9Mo_0.1O_y nanosupports also exhibits improved stability against Pt sintering under a potential cycling regime (3000 cycles from 0.4 V to 1.0 V vs. RHE) due to Strong Metal-Support Interaction (SMSI). Moreover, the role of oxygen vacancies on oxide surface in enhancing of ORR activity was also elucidated by the computational approach.