Constructing highly durable reversal-tolerant anodes via integrating high-surface-area Ti₄O₇ supported Pt and Ir@IrO_x for proton exchange membrane fuel cells

Fuel starvation during the fuel cell operation inevitably leads to high potential anodes, which causes carbon corrosion and catalyst layer collapse and poses a challenge to the durability of proton exchange membrane fuel cells. Herein, Ti₄O₇ with a high specific surface area was synthesized facilely and utilized to replace carbon as the anode catalyst support. Previously, the initial performance of the Ti₄O₇-supported catalyst was obstructed by the disadvantaged electrical conductivity of Ti₄O₇. This work obtains a comparable polarization performance after optimizing the Ti₄O₇-supported anode catalyst layer parameters by shortening the electron transfer pathway and increasing metal coverage. Meanwhile, reversal-tolerant anodes (RTAs) were fabricated by the traditional IrO₂ addition and core-shell structured Ir@IrO_x to validate the applicability of the Ti₄O₇ support. Typically, the Ir@IrO_x/Pt/Ti₄O₇-fabricated RTA with low Ir loading displays an approximately ten times longer reversal time (6 hours) and two orders of magnitude lower degradation rate than a conventional carbon-supported counterpart. The degradation origin of the Ti₄O₇-supported anodes was also studied by postmortem characterizations, pointing to the Pt oxidation caused by the formation of TiO_x thin layers on the Pt surface. The study aims to promote the development of carbon-free anodes and provide a bright perspective for practical high-performance, low-degradation, and cost-friendly RTA fabrication.