Unveiling the local structural change upon activation and cycling-induced ageing of carbon nitride-based Pt-Ni electrocatalyst for low tempe

This experiment investigates activation and ageing of electrocatalysts (ECs) for the oxygen reduction reaction (ORR) in PEM fuel cells. It focuses on hierarchical ECs with PtNix (x=1, 0.3) active sites wrapped in carbon nitride shells (CN HECs), compared to benchmark Pt/C ECs. Activation optimizes structure, increases accessible sites, enhances electronic interactions, and strengthens support bonding, improving initial ORR performance.Accelerated ageing tests then assess long-term stability. Tracking Pt L3-edge and Ni K-edge changes via XAS reveals structural evolution during these processes using a patented electrochemical cell. Previous XAS experiment CH-6948 detected metal agglomeration, alloy formation, and composition changes impacting ORR. Preliminary results show Pt/C ECs degrade more with ageing than CN H-ECs. Overall,the study links activation to ageing resistance, guiding durable EC design for better PEMFCs and encourages green hydrogen adoption.