Engineering low-coordination atoms on RhPt bimetallene for 12-electron ethanol electrooxidation

Abstract

Low-coordination atoms can efficiently activate the adsorbates to facilitate electrochemical reactions characterized by slow kinetics and multi-electron transfer processes, yet achieving a high exposure ratio of low-coordinated atoms on the catalyst surface remains extremely challenging. Herein, we present the synthesis of a three-dimensional perforated RhPt bimetallene through an effective etching-replacement strategy, which exhibits numerous pores with an average size of approximately 1.4 nm, a rugged two-dimensional surface, and additional ultrafine RhPt nanocrystals with an average size of about 1.1 nm, revealing the virtues of abundant low-coordination atoms. RhPt bimetallene reveals outstanding activity (1.77 A mg⁻¹) and remarkable selectivity for 12-electron ethanol oxidation to CO₂, achieving 100% fuel utilization efficiency at 60 °C. In-depth investigation through in situ Fourier transform infrared reflection spectroscopy, coupled with theoretical calculations, shows that Rh–Pt bimetallic active sites with low coordination characteristic facilitate the C1 pathway and the removal of CO* intermediates for ethanol oxidation reaction. This work not only introduces an effective strategy for constructing model nanostructures with highly active low-coordination atoms, but also sheds light on the fundamental role of bimetallic active sites featuring low-coordination numbers in promoting the complete electrooxidation process.