Durable Nitrogen-Containing Carbon-Shell-Encapsulated Pt/C Catalysts Synthesized by the Direct Pyrolysis of Pt-TPTZ Complexes for a Polymer Electrolyte Membrane Fuel Cell

Proton-exchange membrane fuel cells (PEMFCs) have emerged as a promising energy conversion technology due to their high energy efficiency, low operating temperature, zero pollutant emissions, and carbon neutrality, rendering them highly attractive for transportation and stationary power applications. However, enhancing the durability of Pt-based oxygen reduction reaction (ORR) catalysts while maintaining high activity remains a critical challenge for PEMFCs. In this study, a Pt/C@TPTZ450 ORR catalyst was synthesized via the surface modification of Pt/C with the nitrogen-containing organic small-molecule 2,4,6-tris(2-pyridyl)-1,3,5-triazine (TPTZ), resulting in the formation of an ultrathin nitrogen-containing coating layer (≈0.5 nm) that effectively stabilizes the catalyst structure. The modified catalyst exhibits enhanced ORR mass activity in rotating disk electrode (RDE) measurements compared with pristine Pt/C. More importantly, the TPTZ-derived coating effectively restricts the undesirable processes of Pt catalyst particle growth, carbon support corrosion, Pt migration, and Pt leaching during long-term operation. Consequently, the durability of the Pt/C@TPTZ450 catalyst is significantly improved compared to that of the pristine Pt/C catalyst. After 30,000 cycles of accelerated stress tests (ASTs), the membrane electrode assembly (MEA) with the Pt/C@TPTZ450 catalyst exhibits a voltage decay of only 22 mV at a current density of 0.8 A/cm2, accompanied by an electrochemical active surface area decay of 38.42%. These durability metrics fully meet the technical targets set by the U.S. Department of Energy (DOE) for proton-exchange membrane fuel cell catalysts. Furthermore, this work provides new insights and practical solutions for enhancing catalyst durability.