Performance Optimization Studies of Thermal Annealing on Pd-Co/C Cathode Electrocatalyst for Anion Exchange Membrane Fuel Cells

Anion exchange membrane fuel cells (AEMFCs) are the most feasible choice of catalyst due to their high efficiency and scale of commercialization. However, the challenge posed by the sluggish kinetics of AEMFCs can only be countered by an effective electrocatalyst that enhances the reaction kinetics and, thereby, the fuel cell performance. The Pd-Co/C cathode catalyst is a promising choice of electrocatalyst, with the phenomenon of alloying playing a key role at appropriate temperatures and residence time distributions of annealing due to the influence of the lattice parameter, electrochemically active surface area (ECSA), and particle size. After completing the synthesis of 20 wt.% Pd-Co/C, the catalyst was treated under various annealing and loading conditions. This was subsequently followed by a series of physicochemical and electrochemical characterizations that verified the successful synthesis of the catalyst material, paving a path to optimizing the annealing temperature, annealing residence time, and catalyst loading. Further, proceeding with the fuel cell test runs with multiple profiles of the above parameters resulted in the optimization of the annealing temperature, residence time of annealing, and catalyst loading, and it was subsequently concluded that the best performance of the fuel cell was achieved when the Pd-Co/C catalyst was annealed at 500 °C for a duration of 1 h and loaded at 0.25 mg/cm2, which resulted in an impeccable power density of 724 mW/cm2.