Exploring the synergistic impact of switched gold and platinum nanocatalyst layers towards methanol electrooxidation reaction

The quest for highly effective and durable electrocatalysts for methanol oxidation remains a contemporary research endeavour in the direct methanol fuel cells (DMFC) domain. Pt-based electrocatalysts remain the front-runner in DMFC due to their exceptional catalytic performance and stability irrespective of cost. In this regard, the present investigation delves into tuning the inherent synergy of the Au/Pt bi-metallic catalytic system by switching the gold (Au) and platinum (Pt) nanocatalyst layers toward boosting methanol electro-oxidation. The sequential electrodeposition strategy was adopted to form distinct catalyst models; Pt on Au (Au/Pt), Au on Pt (Pt/Au), and Au–Pt alloy. Interestingly, switching the outer layer of Au into Pt nanostructures via changing the order of electrodeposition (Pt/Au to Au/Pt), the resulting Au/Pt electrocatalyst exhibits remarkable efficiency and long-term durability regarding methanol oxidation reaction in comparison with mono-metallic Pt and commercial Pt–C. The synergistic effect attained by tuning Au/Pt catalyst layers arises from the following fact that the top Pt layer favours the direct methanol adsorption and its oxidation, while the underlying Au assists the transformation of electroformed CO-like intermediate species into CO₂ and protects the Pt surface from the CO surface poisoning, which makes present catalyst perform better for long duration.