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

Abstract

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.