Hexagonal PtBi Intermetallic Inlaid with Sub-Monolayer Pb Oxyhydroxide Boosts Methanol Oxidation

Engineering multicomponent nanocatalysts is effective to improve electrocatalysis in many applications, yet it remains a challenge in constructing well-defined multimetallic active sites at the atomic level. Herein, the surface inlay of sub-monolayer Pb oxyhydroxide onto hexagonal PtBi intermetallic nanoplates with intrinsically isolated Pt atoms to boost the methanol oxidation reaction (MOR) is reported. The well-defined PtBi@6.7%Pb nanocatalyst exhibits 4.0 and 7.4 times higher mass activity than PtBi nanoplates and commercial Pt/C catalyst toward MOR in the alkaline electrolyte at 30 degrees C. Meanwhile, it also achieves a record-high mass activity of 51.07 A mg(Pt)(-1) at direct methanol fuel cells operation temperature of 60 degrees C. DFT calculations reveal that the introduction of Pb oxyhydroxide on the surface not only promotes the electron transfer efficiency but also suppresses the CO poisoning effect, and the efficient p-d coupling optimizes the electroactivity of PtBi@6.7%Pb nanoplates toward the MOR process with low reaction barriers. This work offers a nanoengineering strategy to effectively construct and modulate multimetallic nanocatalysts to improve the electroactivity toward the MOR in future research.

Automated summary

The surface inlay of sub-monolayer Pb oxyhydroxide onto hexagonal PtBi intermetallic nanoplates can enhance the activity of methanol oxidation reaction, providing an effective nanoengineering strategy.