Heterostructured Copper–Palladium Phosphide Particles as Efficient Electrocatalysts for Ethanol Oxidation and Oxygen Reduction in Direct Ethanol Fuel Cells

Engineering lattice strain, electronic structure, and crystallinity in palladium alloys offers a promising approach to significantly enhance their electrocatalytic performance. In this work, we present a versatile strategy to synthesize Pd-based phosphide alloys integrated with non-noble metal atoms (Pd-M-P; M = Co, Ni, Cu), characterized by expanded lattice structures and a crystalline-amorphous core-shell architecture. Catalytic performance assessments revealed that CuPdP exhibits an impressive mass activity of 7.96 A mg_Pd^-1 for the ethanol oxidation reaction (EOR), which is 10.6 times higher than that of commercial Pd/C. This performance enhancement can be attributed to the precisely engineered lattice tensile strain and the strong p-d hybridization interaction between P and Pd. Density functional theory calculations further confirmed that these factors facilitate enhanced OH adsorption and weakened CO adsorption, thereby significantly improving EOR performance. This study presents an effective strategy for the atomic-level engineering of palladium alloy nanomaterials to achieve good electrocatalytic performance, providing a method for designing highly active catalysts.