Conductive Si doped metal oxide fuel cell catalyst supports: understanding the role of Si content

Abstract

Current proton exchange membrane fuel cell (PEMFC) catalysts commonly use platinum supported on carbon (Pt/C) which is susceptible to corrosion, thus a highly conductive and stable Ti3O5 doped by Si (TOS) conductive metal oxide catalyst support is reported. The TOS support was optimized for 20 wt% Si and surface area. The support was studied under intensive electrochemical durability tests and exhibited impressive durability and stability, narrow band gap and high electronic conductivity. The TOS support was platinized (Pt/TOS) and possessed high stability under and electrochemical durability test while experiencing ca. 15% loss to the electrochemical surface area (ECSA) compared to the commercial Pt/C catalyst which decayed by 90%. The Pt/TOS catalyst maintained adequate electroactivity and stability toward the ORR and produced a maximum power density of 900 mW cm-2 compared to 850 mW cm-2 for Pt/C.