Engineering Convex Polyhedral PdBiPt Ternary Catalysts via Seed Mediation for Efficient Methanol Oxidation

Crafting electrocatalysts that are both highly reactive and durable for the methanol oxidation reaction (MOR) is of paramount importance to real-world deployment of direct methanol fuel cells. This work presents a controllable two-step hydrothermal synthesis of ternary PdBiPt convex polyhedral (CP) catalysts. Structural analysis confirmed these to be face-centered cubic alloys. The galvanic replacement process led to partial dissolution of Pd and Bi while simultaneously causing lattice strain, surface roughening, and the formation of abundant defects. X-ray photoelectron spectroscopy results revealed that Pt exhibited a higher surface concentration and that there were strong electronic interactions between Pd, Pt, and Bi. Electrochemical tests demonstrated that the optimized PdBiPt-S2 CP exhibits outstanding MOR mass activity (10.67 A mg–1) in alkaline media, surpassing both the PdBi seeds and commercial Pt/C, along with excellent reaction kinetics and long-term stability. In situ Fourier transform infrared spectroscopy revealed that the reaction follows an efficient formate pathway, effectively circumventing CO poisoning. This work provides a strategy for designing high-performance multicomponent alloy electrocatalysts.