Interfacial metal–coordinated bifunctional PtCo for practical fuel cells

Platinum (Pt) has been documented as the top-tier fuel cell catalyst, yet it faces a notable challenge regarding its poor CO tolerance and sluggish oxygen reduction reaction (ORR) in proton exchange membrane fuel cells (PEMFCs), particularly when using CO-contaminated blue and gray H₂. Here, we present an interfacial metal coordination strategy to design a bifunctional platinum-cobalt (PtCo) intermetallic catalyst integrated with a tin-nitrogen-carbon (Sn-N-C) support, which forms Pt-Sn-N bonds that substantially boost both ORR activity and CO tolerance. The PtCo/Sn-N-C-made fuel cell achieves a topmost peak power density of 2.11 watts per square centimeter in 100 parts per million (ppm) of CO-containing H₂, surpassing all previously reported PEMFCs. In addition, it operates stably at a rated voltage for over 710 hours in 100 ppm of CO/H₂-air. This work demonstrates the feasibility of fuel cells directly using CO-contaminated gray & blue H₂, paving the way for PEMFC-driven energy vehicles.