Synthesis of carbon-supported multimetallic palladium-based electrocatalysts for direct ethanol fuel cells (DEFCs).

The commercialization of direct ethanol fuel cells (DEFCs) is hindered by platinum dependency, catalyst degradation, and high costs. This work addresses these challenges by developing carbon-supported trimetallic PdAuM/C (M = Rh, Ir, Ag) electrocatalysts for the ethanol oxidation reaction (EOR). Through a controlled synthesis protocol, PdAuM/C nanoparticles (3.1-6.7 nm) with alloyed structures were characterized by XRD, TEM, EDX, and XPS. Electrochemical analyses (CV, CA, EIS) in alkaline media revealed unprecedented EOR activity: PdAuRh/C achieved a peak current density of 10,500 mA·mg⁻¹Pd and onset potential of - 680 mV vs. NHE-5.8× higher current and 195 mV lower overpotential than monometallic Pd/C (1,800 mA·mg⁻¹Pd, - 485 mV). PdAuIr/C and PdAuAg/C also outperformed Pd/C, though PdAuAg exhibited a typical dual oxidation peaks. The synergistic electronic effects in PdAuRh/C minimized CO poisoning and maximized active sites, positioning it as a sustainable, high-performance alternative to Pt-based catalysts for DEFCs.