Destabilized FeNC via H2 Treatment for Co-supported L10-PtM and L12-Pt3M with Increased ORR Performance

Intermetallic Pt with an L10-PtM structure has been considered a promising oxygen reduction reaction (ORR) catalyst for proton exchange membrane fuel cells (PEMFC) due to its reduced Pt usage and high activity. However, it suffers from issues of agglomeration during high-temperature annealing compared with its L12-Pt3M counterparts. Meanwhile, attempts to utilize the advantages of both L10-PtM and L12-Pt3M are often limited by their difficulties in material synthesis. Herein, we support intermetallic Pt particles on single-atom metal–nitrogen–carbon (M–N–C) and destabilized Fe–N sites via H2 pretreatment during the carbonization. As a result, the synthesized O-PtCo@FeNC(5H) sample displays co-presence of both L10-PtM and L12-Pt3M phases with a size distribution of 3.20 ± 0.52 nm, achieving enhanced catalytic activity and stability (mass activity (MA) = 1.23 A mgPt–1, 89.1% MA retention after 30,000 cycles). Furthermore, the membrane electrode assembly (MEA) test shows an enhanced MA of 0.471 A mgPt–1 and a peak power density of 1.288 W cm–2 in H2–air conditions. Additionally, the synthetic strategy can be extended to other M–N–C supports, including CoNC and NiNC. Overall, this work demonstrates a strategy for integrating the advantages of L10-PtM and L12-Pt3M by the use of a modified M–N–C single-atom support.