Tunable Synthesis of N,C-Codoped Ti3+-Enriched Titanium Oxide Support for Highly Durable PEMFC Cathode

The hydrogen economy expansion triggered studies on the durability of hydrogen-powered proton-exchange membrane fuel cells (PEMFCs), which revealed that their performance is largely hindered by the degradation of cathode support. Herein, Ti 3+ -enriched N,C-codoped mixed-phase TiO 2 nanoparticles featuring a reduced (compared to that of pristine TiO 2 ) band gap and containing Ti 3+ ions, oxygen vacancies, and Ti–X bonds (X = O, OH, N, C) were synthesized as a durable PEMFC cathode support by annealing. The extent of doping was controlled by adjustment of dopant (urea) loading, while the abundance of defect sites resulted in an enhanced metal–support interaction (i.e., Pt–Ti bonding) for Pt/N,C-codoped TiO 2, as confirmed by the shift of the most prominent Pt 0 peak of Pt/N,C-codoped TiO 2 to lower binding energies (by 0.96 eV) relative to that of Pt/C. Electrochemical performance testin…