Pt Nanoparticles Dispersed on Hollow NiP Alloy Nanospheres as Catalysts for Methanol Electrooxidation

This paper investigates the catalytic efficiency of hollow nanosphere─supported catalysts loaded with precious metal Pt and modified with NiP alloy nanoparticles in the methanol oxidation reaction. The incorporation of NiP alloy modulates the electronic structure of Pt via electron transfer, which not only results in a downward shift of the D-band center but also enhances conductivity. Consequently, this improves both catalytic activity and selectivity. Notably, the Pt–NiP/C catalyst with 200 mg sodium hypophosphite precursor content demonstrated the highest electrochemical surface area (ECSA) of 66.38 m²·g_Pt^–1and mass activity of 737.4 mA·mg_Pt^–1, with its mass activity approximately 2.38 times that of the conventional Pt/C catalyst. Electrochemical impedance spectroscopy (EIS) analysis showed that the Pt–NiP/C 200 mg catalyst has the lowest charge transfer resistance, indicating a more efficient charge transfer mechanism and a higher methanol oxidation rate. Furthermore, the current density of this catalyst is 5.3 times that of the original Pt/C catalyst and exhibits excellent stability. These research results not only provide an in-depth understanding of the catalytic mechanism of methanol oxidation but also serve as an important reference for the development of more efficient and durable platinum-based catalysts, thereby advancing the development of fuel cell technology.