Boosting the Durability of High‐Pt‐Content Fuel Cell Cathode Catalysts Through TaO_x Decorating

Abstract Enhancing the durability of carbon‐supported platinum catalysts (Pt/C) for the oxygen reduction reaction remains a significant challenge in the field of proton exchange membrane fuel cells (PEMFCs), especially for catalysts with high‐Pt contents. Herein, a TaO_x decorating strategy that is capable of effectively boosting the durability of Pt/C catalysts even with a high‐Pt content of 50 wt.% is introduced. This strategy involves introducing reducible Ta₂O₅ nanoparticles into carbon supports, depositing Pt nanoparticles, and finally conducting high‐temperature H₂ annealing to convert reducible Ta₂O₅ nanoparticles into amorphous TaO_x decorating the Pt nanoparticles. The annealing temperature found in the Ta₂O₅ incorporation step is critical for the formation of reducible Ta₂O₅ nanoparticles, which, in turn, determines the continuity of the TaO_x subsequently formed around the Pt nanoparticles. By controlling annealing temperature, the formation of a relatively continuous TaO_x distribution on the Pt nanoparticle surface is achieved, thereby maximizing the interaction between Pt and TaO_x and enhancing the electrochemical stability of Pt nanoparticles. Following the accelerated durability test, the resulting high‐Pt‐content catalyst demonstrates an array of exceptional durability metrics, including an electrochemical surface area loss of 30%, a mass activity loss of 35%, and a voltage loss of 22 mV at 0.8 A cm^‒2.