Carbon confinement engineering of ultrafine Pt-based catalyst for robust electrochemical oxygen reduction reaction
Dongping Xue, Yu Zhao, Huicong Xia, Jianliang Cao, Yan Wang
Abstract
Proton exchange membrane fuel cells (PEMFCs) critically depend on efficient oxygen reduction reaction (ORR) catalysts at the cathode, directly influencing their efficiency, durability, cost, and scalability. Commercial Pt/C catalysts face challenges from Pt scarcity, high costs, and instability, driving research toward ultrafine Pt-based alternatives. Herein, the kinetics and mechanisms of ORR are systematically summarized first. The main degradation mechanisms of Pt-based catalysts are further analyzed, laying the foundation for understanding the necessity of carbon confinement engineering to enhance durability. Subsequently, the review explores the mechanisms of nanospace and chemical confinement, methods for constructing ultrafine Pt-based catalysts leveraging these confinement effects, and specific strategies for optimizing the performance of ultrafine Pt-based catalysts to effectively bridge the performance gap between rotating disk electrode (RDE) and membrane electrode assembly (MEA). Furthermore, this review concludes that the comprehensive development of multi-scale, multi-component, and highly ordered ultrafine alloy nanostructures and new stable supports will provide more options for the rational design of low-cost, high-performance Pt-integrated ORR catalysts. Finally, the development trends and challenges faced by carbon-confined Pt-based PEMFCs are discussed, and the application prospects of confinement engineering in multiple fields are prospected.