Surface engineered PdNFe₃ intermetallic electrocatalyst for boosting oxygen reduction in alkaline media

Surface engineering has been identified as an effective way to maximize the utilization of noble atoms and facilitate the oxygen reduction reaction. However, a cost-effective and highly durable platform for tailoring the electrocatalytic activity, is still absent. Herein, we demonstrate a new and promising catalytic material of antiperovskite-typed PdNFe₃ and construct a high performance PdNFe₃ @Pd catalyst with atomic layers of strained Pd shell. The PdNFe₃ @Pd/C catalyst presents a high mass activity (MA) of 1.14 A mg⁻¹_Pd at 0.9 V, which is 9 and 6 times higher than those of the Pt/C and Pd/C, respectively. More importantly, the excellent performance of PdNFe₃ @Pd/C was also verified in anion-exchange membrane fuel cells and rechargeable Zn−air batteries. Density functional theory calculations reveal that the strain effect aroused by the lattice mismatch between PdNFe₃ core and Pd shell contributes to the enhanced ORR performance by optimizing the binding strength of oxygen intermediates on Pd.