Nitrogen-Coordinated Cobalt Single Atoms for Achieving Pt with Superhigh Power and Stability in Proton Exchange Membrane Fuel Cells

The Co single atom-coordinatedPt catalyst demonstratesexcellent ORR activity and durability for the fuel cell applications. To achieve widespread implementation of proton exchangemembranefuel cells (PEMFCs), developing efficient electrocatalysts with excellentactivity and durability is of great significance. However, it stillremains a big challenge to enhance the durability of low Pt catalystsand simultaneously maintain their high activity under PEMFC operationconditions. In this work, an innovative strategy has been proposedto couple nitrogen-coordinated Co single atoms with Pt nanoparticles(NPs) for a superhigh power and stable catalyst in PEMFCs. Due tothe strong metal-support interaction and synergistic effectof Pt and Co atoms, the Pt-NP-Co1NC catalystshows excellent catalytic activity and durability in both the liquidhalf-cell and PEMFC operations, achieving a high power density of1.38 W & BULL;cm(-2) and superior stability of 6 mVcell voltage loss at 1.0 A & BULL;cm(-2) after 5000potential cycles in PEMFC applications, which is better than thatof 1.20 W & BULL;cm(-2) and 16 mV voltage loss for thecommercial Pt/C catalyst. Comprehensive investigations reveal thatsuch excellent durability is ascribed to the anchoring effect of Co-1-Nx sites with Pt, which strengthen the interactionbetween Pt and the nanosheet support, thus significantly mitigatingPt NP ripening and agglomeration, and enhancing catalyst stabilityunder challenging PEMFC operation conditions. This work of integrationnitrogen-coordinated Co atoms with Pt may cause profound researchon a multiscale design of long-term stable electrocatalyst in PEMFCapplications.

Automated summary

An innovative strategy of coupling nitrogen-coordinated Co single atoms with Pt nanoparticles has been proposed for a superhigh power and stable catalyst in proton exchange membrane fuel cells. The catalyst shows excellent catalytic activity and durability in both the liquid half-cell and PEMFC operations, outperforming the commercial Pt/C catalyst.