The nature of local oxygen radical boosts electrocatalytic ethanol to selectively generate CO2

Abstract

Developing a high-activity and antitoxic electrocatalyst is still a demanding task. Enhancing the enrichment of oxygen species on catalysts is beneficial for thorough oxidation of ethanol to generate CO₂, but the role of oxygen radicals in the process of ethanol oxidation is still ambiguous. Herein, an artificial oxidase that can catalyze oxygen to generate reactive oxygen species (ROS) in-situ has been applied in EOR for the first time and the roles of •OH, •O₂⁻, and ¹O₂ in complete oxidation of ethanol were investigated. The mass activity of EOR is 18.2 A mg_Pt⁻¹ in 1 mol L⁻¹ KOH and the CO₂ selectivity is 98.7%. The research showed that Sn element could optimize coordination mode on catalyst surface, which enhanced oxidase activity of the catalyst. Explored the intermediates of the reaction and evaluated the performance of the catalyst using in-situ infrared testing technology. Theoretical calculations indicate that C–C bond breakage of *CH₃CO to generate *CH₃ and *CO is potential determination steps in the C1 pathway. When singlet oxygen is present on the PtSn IM/C surface, the dissociation energy of C–C bond is –0.51 eV, which is lower than the 1.07 eV of hydroxyl radicals and –0.47 eV of superoxide anions.