The silver-platinum interaction empowering stable 12-electron ethanol oxidation

Abstract

Highly active and stable electrocatalysts for ethanol oxidation reaction (EOR) are critical for the widespread adoption of direct ethanol fuel cells (DEFCs). However, the low efficiency of C–C bond cleavage of commercial electrocatalysts not only leads to incomplete ethanol oxidation but also results in the accumulation of poisoning CO species. In this work, silver-platinum hollow nanocubes (AgPt hNCs) are designed and synthesized to achieve high selectivity for the complete 12-electron EOR in an alkaline electrolyte. AgPt hNCs demonstrate a Faradaic efficiency of up to 88.2 % at the potential of 0.70 V for the C1 pathway and exhibit a 6.3-fold EOR mass activity than commercial Pt black at the potential of 0.81 V. Moreover, the oxyphilic nature of Ag imparts exceptional long-term stability to AgPt hNCs. Theoretical calculations reveal that the electronic interaction between Pt and Ag effectively modifies the d-band properties of surface Pt atoms, thereby optimizing the adsorption behavior of key intermediates, promoting the dehydrogenation of CH₃CO* to CH₂CO*, and facilitating C–C bond cleavage. The present work provides both theoretical and experimental insights into the utilization of Ag-based alloy catalysts for high-performance DEFCs.