Strong Electron-Withdrawing Effect Activates Metal-Free Carboxylate Anion into Efficient Active Sites for Electrocatalytic Acetylene Semihydrogenation

作者：Rui Bai, Zhihao Zhao, Mingxuan Liu, Wenxiu Ma, Jin Lin, Siying An, Jiaxin He, Zhenpeng Liu, Lei Zhang, Hui Mei, Jian Zhang · 发表于：Journal of the American Chemical Society · 年份：2025 · DOI：10.1021/jacs.4c17260 · 被引用次数：39 · 研究领域：Electrocatalysts for Energy Conversion、CO2 Reduction Techniques and Catalysts、Ammonia Synthesis and Nitrogen Reduction

The exploration of novel and high-performance organo-electrocatalysts with well-defined active sites is vital for understanding catalytic mechanisms and replacing metal-based catalysts, but remains a formidable challenge. Here, we report metal-free trifluoroacetate as a new organo-electrocatalyst, where the strong electron-withdrawing trifluoromethyl (−CF 3 ) group intrinsically transforms the neighboring carboxylate anions (−COO – ) into highly efficient active sites for electrocatalytic acetylene semihydrogenation. The electrophilic acetylene molecule bonds to the negatively charged O – sites of the carboxylate anion via the σ-configuration. Benefiting from precise molecular engineering of electron-withdrawing groups, the ethylene partial current density presents a volcano relationship with the total natural charge of the −COO – anions. In 1 M KOH aqueous solution, trifluoroacetate delivers an ethylene partial current density of 260 mA/cm 2 with an ethylene Faradaic efficiency of 96.8% at −0.9 V versus the reversible hydrogen electrode (RHE) under a pure acetylene atmosphere, outperforming metal-based electrocatalysts. This work presents a new type of high-activity organo-electrocatalysts with −COO – anions as active center and promises its application in electrocatalysis.