Controlled Synthesis of Ultrahigh-Loading Pt–Co Intermetallic Compounds for Superior Oxygen Reduction Reaction

High-loading Pt-based intermetallic compound (IMC) electrocatalysts are crucial in proven proton-exchange membrane fuel cell (PEMFCs) products. This work prepares a Pt–Co IMC (marked as O-PtCo/C with SiO2) by using a two-step annealing strategy with a Pt loading of up to 58.78 wt % and an average size of ca. 4.7 nm. The O-PtCo/C with SiO2 displays a great oxygen reduction reaction activity (0.44 A mgPt–1) and stability (∼2.3% loss after 10K cycles of ADT). Furthermore, the catalyst demonstrates an output power density of up to 1242 mW cm–2 in the membrane electrode assembly test. All benefit from the controlled synthesis of ordered structures and small sizes. This study develops a way to promote the commercialization of high-loading Pt/Co IMCs in fuel cells.