Oxygen spillover on supported Pt-cluster for anti-CO-poisoning hydrogen oxidation

Reducing Pt loading in the anodic hydrogen oxidation reaction (HOR) and concurrently increasing mass activity and CO tolerance are essential for advancing proton exchange membrane fuel cells (PEMFCs). Here, an electrocatalyst of 1.7 wt% Pt clusters loaded on a hollow bowl-like W₃O/WC heterostructure is designed to increase the anti-CO-poisoning HOR. Due to its unique electron delocalization effect, the W₃O/WC heterostructure serves as a warehouse to share electrons with Pt; this simultaneously lowers the HOR barrier and accumulates the hydroxyl radicals (•OH) to accelerate CO oxidation. The Pt‒O bond originating from the oxygen spillover effect of W₃O promotes hydrogen and CO oxidation, whereas the lattice‒O consumed in W₃O replenished through water dissociation. The resultant electrocatalyst exhibits mass activity of 469 A g^‒1 at 50 mV and anti-toxicity even at 2000 ppm CO. The PEMEC delivers a peak power density of 1.63 W cm^‒2 and maintains considerable anti-CO poisoning performance.