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

Abstract

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. In this contribution, the electrocatalytic hydrogen oxidation activity and CO resistance capability of Pt clusters are enhanced through the combination of the electron delocalization effect, which allows W3O/WC to share electrons with Pt clusters, and the oxygen spillover effect.