High-performance of ultra-low Pt-loaded PEMFCs: carbon-encapsulated CoFe alloy supported Pt nanoparticles as high-efficiency electrocatalysts

Abstract

Developing efficient ultra-low Pt-loaded proton exchange membrane fuel cell (PEMFC) cathode catalysts is crucial for practical applications. Nevertheless, the trade-off between active site efficiency and structural stability makes it challenging to simultaneously achieve high activity and durability. Herein, a dual-anchoring strategy is designed for the construction of efficient and stable ultra-low Pt-loaded PEMFC catalysts. This catalyst inhibited the migration of Pt through the physical confinement of the support. Meanwhile, the CoFe bimetallic synergy regulates the electronic structure of Pt, achieving high activity and long lifetime of membrane electrode assemblies (MEAs) with ultra-low Pt loading (0.1 mg_Pt cm⁻²). The current density of MEAs reached 1.15 A cm⁻² at 0.7 V (H₂-Air, 150 kPa), and the performance was improved by 19% compared to commercial Pt/C. The voltage loss of MEAs with Pt/CoFe-NOC was 2 mV at 0.8 A cm⁻² after the accelerated durability test (ADT) of 30 000 cycles, which greatly outperformed Pt/C (68.2 mV). Density functional theory (DFT) calculations revealed that the CoFe support improves the desorption of oxygen-containing intermediates by modulating the d-band center (−2.09 eV) and work function (4.52 eV) of Pt. This work provides new insights for the development of high-performance ultra-low Pt-loaded PEMFCs.