Pt–W bimetallic alloys as CO-tolerant PEMFC anode catalysts

Pt–W nanoalloys with compositions ranging from Pt3W to PtW2 were explored as electrocatalysts for hydrogen oxidation reaction (HOR). It is shown that alloying Pt with W can lead to significantly enhanced electrocatalytic activity for HOR, with nearly 4 times increase in the exchange current density as compared with pure Pt. What's more, these Pt–W alloys possess superior CO tolerance to Pt and PtRu, mainly due to the weakened bonding of CO on their Pt-enriched surfaces.

► Pt-enriched surface even at low Pt composition such as PtW2.
► Much higher exchange current density of Pt–W alloys for HOR than pure Pt.
► Much better CO-tolerance of Pt–W alloys than PtRu.
► CO-tolerant hydrogen oxidation of Pt–W alloys through a detoxification mechanism rather than a bifunctional mechanism.