Guazzi Simone, Dürr Robin N, Bogo Andrea, Bassan Elena, Arias-Ferreiro Goretti, Cacioppo Michele, Prato Maurizio, Bonchio Marcella
Department of Chemical and Pharmaceutical Sciences, University of Trieste, Via Licio Giorgieri 1, Trieste 34127, Italy.
INSTM, National Interuniversity Consortium of Materials Science and Technology, UdRTrieste 34127, Italy.
J Am Chem Soc. 2025 Sep 24;147(38):34840-34848. doi: 10.1021/jacs.5c10817. Epub 2025 Sep 11.
The electrosynthesis of ethyl acetate (EtOAc) by oxidative esterification of aqueous (up to 20% water) ethanol (EtOH) is performed by employing the tetraruthenate polyoxometalate [Ru(μ-O)(μ-OH)(HO)(γ-SiWO)] (RuPOM) electrocatalyst with carbon nanohorns (CNHs) as a heterogeneous support. This strategy involves a voltage-gated electro-adsorption of RuPOM on CNH-modified glassy carbon anodes with favorable interfacial dynamics, maintained under electrocatalytic conditions. These conditions are reached through the continuous reconstruction of the organic/inorganic interface (catch-and-release), as probed by converging thermal, microscopic, and electrochemical analyses. In fact, control experiments reveal that both pristine and N-doped CNHs display a RuPOM loading in the range 13-18 nmol mg with a remarkable ∼100 mV onset potential anticipation and current enhancement in the range 400-700% compared to the homogeneous conditions. By adopting the "catch-and-release" protocol, electro-esterification of aqueous EtOH features long-term stability of the productive current in the mA range ( ≈ 2 mA cm at +1.2 V vs Ag/AgCl probed up to 18 h), with Faradaic efficiencies, FE, of >90%. This effect is attributed to the crucial role of CNHs hydrophobicity to control hydrolysis equilibria, thus outperforming the solution-phase behavior, which levels off at FE < 60%.
通过使用以碳纳米角（CNHs）作为非均相载体的多金属氧酸盐四钌酸盐[Ru(μ-O)(μ-OH)(HO)(γ-SiWO)]（RuPOM）电催化剂，对含水（高达20%水）乙醇（EtOH）进行氧化酯化来实现乙酸乙酯（EtOAc）的电合成。该策略涉及RuPOM在具有良好界面动力学的CNH修饰玻碳阳极上的电压门控电吸附，并在电催化条件下保持。通过热分析、显微镜分析和电化学分析相结合的方法探究发现，这些条件是通过有机/无机界面的持续重构（捕获-释放）来实现的。事实上，对照实验表明，与均相条件相比，原始的和氮掺杂的CNHs都显示出13 - 18 nmol mg范围内的RuPOM负载量，起始电位提前约100 mV，电流增强400 - 700%。通过采用“捕获-释放”方案，含水EtOH的电酯化具有毫安范围内生产电流的长期稳定性（在相对于Ag/AgCl为 +1.2 V时约为2 mA cm，探测长达18小时），法拉第效率FE > 90%。这种效应归因于CNHs疏水性在控制水解平衡方面的关键作用，从而优于溶液相行为，溶液相行为在FE < 60%时趋于平稳。
