Inducing Covalent Atomic Interaction in Intermetallic Pt Alloy Nanocatalysts for High‐Performance Fuel Cells

The harsh working environments of proton exchange membrane fuel cells (PEMFCs) pose huge challenges to the stability of Pt-based alloy catalysts. The widespread presence of metallic bonds with significantly delocalized electron distribution often lead to component segregation and rapid performance decay. Here we report L1₀ -Pt₂ CuGa intermetallic nanoparticles with a unique covalent atomic interaction between Pt-Ga as high-performance PEMFC cathode catalysts. The L1₀ -Pt₂ CuGa/C catalyst shows superb oxygen reduction reaction (ORR) activity and stability in fuel cell cathode (mass activity=0.57 A mgPt ⁻¹ at 0.9 V, peak power density=2.60/1.24 W cm⁻² in H₂ -O₂ /air, 28 mV voltage loss at 0.8 A cm⁻² after 30 000 cycles). Theoretical calculations reveal the optimized adsorption of oxygen intermediates via the formed biaxial strain on L1₀ -Pt₂ CuGa surface, and the durability enhancement stems from the stronger Pt-M bonds than those in L1₁ -PtCu resulted from Pt-Ga covalent interactions.