VOx Matrix Confinement Approach to Generate Sub‐3 nm L10‐Pt‐Based Intermetallic Catalysts for Fuel Cell Cathode

Abstract Pt‐based intermetallic compounds (IMCs) are considered as a class of promising fuel cell electrocatalysts, owing to their outstanding intrinsic activity and durability. However, the synthesis of uniformly dispersed IMCs with small sizes presents a formidable challenge during the essential high‐temperature annealing process. Herein, a facile and generally applicable VO x matrix confinement strategy is demonstrated for the controllable synthesis of ordered L1 0 ‐PtM (M = Fe, Co, and Mn) nanoparticles, which not only enhances the dispersion of intermetallic nanocrystals, even at high loading (40 wt%), but also simplifies the oxide removal and acid‐washing procedures. Taking intermetallic PtCo as an example, the as‐prepared catalyst displays a high‐performance oxygen reduction activity (mass activity of 1.52 A mg Pt −1 ) and excellent stability in the membrane electrode assemblies (MEAs) (the ECSA has just 7% decay after durability test). This strategy provides an economical and scalable route for the controlled synthesis of Pt‐based intermetallic catalysts, which can pave a way for the commercialization of fuel cell technologies.