Microwave-Assisted Polyol Process Enabling Rapid and Controllable Synthesis of Pd–Ni/C Bimetallic Nanocatalysts for Anion Exchange Membrane Fuel Cells

High Resolution Image Download MS PowerPoint Slide Designing rapid and controllable synthesis routes for high-performance electrocatalysts is crucial for advancing alkaline anion exchange membrane fuel cells (AEMFCs). Herein, a microwave-assisted polyol process is developed to efficiently prepare Pd–Ni/C bimetallic catalysts with a tunable nanoparticle structure and compositional distribution, enabling enhanced hydrogen oxidation reaction (HOR) activity under alkaline conditions. Structural analyses indicate that the catalysts consist of Pd-rich and Ni-rich alloy nanoparticles with smaller crystallite sizes than those of monometallic Pd/C and Ni/C catalysts. The coexistence of these nanoparticles improves dispersion and increases the number of electrochemically accessible Pd surface sites, leading to higher electrochemically active surface area (ECSA) and enhanced HOR activity. The effects of polyol type and microwave irradiation time are systematically investigated to elucidate the relationships among synthesis parameters, nanoparticle formation, and electrochemical properties. Among the investigated compositions, catalysts with an intermediate Pd/Ni ratio exhibit the highest ECSA and the best overall performance in single-cell AEMFC tests. This work demonstrates an energy-efficient and reproducible microwave-assisted polyol strategy for controlling nanoparticle size, dispersion, and compositional distribution in Pd–Ni/C catalysts, providing insights into the rational design of Pd-lean anode materials for alkaline hydrogen conversion applications.