Unveiling the Size Effect of Pt-on-Au Nanostructures Towards CO and Methanol Electrooxidation by In-Situ Electrochemical SERS
In-situ monitoring of electrocatalytic processes at solid-liquid interfaces is essential for the fundamental understanding of reaction mechanisms, yet quite challenging. Herein, Pt-on-Au nanocatalysts with a Au-core Pt-satellite superstructure have been fabricated. In such Pt-on-Au nanocatalysts, the Au cores can greatly amplify the Raman signals of species adsorbed on Pt, allowing the in-situ surface-enhanced Raman spectroscopy (SERS) study of the electrocatalytic reactions on Pt. Combined electrochemical method and in-situ SERS, size effects of Pt on the catalytic performance of the core-satellite nanocomposites towards CO and methanol electrooxidation are revealed. It is found that such Pt-on-Au nanocomposites show improved activity and long-term stability for the electrooxidation of CO and methanol with the decrease of the Pt size. This work demonstrates an effective strategy to achieve the in-situ monitoring of electrocatalytic processes and to boost the catalytic performance towards electrooxidation simultaneously.