Ultrafine Pt cluster and RuO2 heterojunction anode catalysts designed for ultra-low Pt-loading anion exchange membrane fuel cells†
Development of high-performance hydrogen oxidation catalysts with ultralow precious metal loading is critical to the development of next-generation anion-exchange membrane fuel cells. Here, a novel Ru-rich Pt–RuO2 heterojunction catalyst was synthesized via a solvothermal process followed by thermal treatment. The Pt–RuO2 catalyst has ultrafine Pt clusters and a heterojunction interface between Pt and RuO2, which facilitates high hydrogen oxidation activity while minimizing adverse adsorption of the phenyl group in the polymer electrolyte. The performance of a membrane electrode assembly employing the Pt–RuO2/C reached a peak power density of 0.77 W cm−2 with an anode Pt loading of 25 μgPt cm−2, achieving a specific power of 31 W mgPt−1 under H2/O2 conditions. The combined analysis of electrode performance and cost indicates that Pt–RuO2/C is one of the most promising catalysts that is approaching the U.S. DOE 2020 performance and cost targets for transportation applications.