Gao Ying, He Meng, Wu Yongmeng, Zhao Bo-Hang, Liu Cuibo, Zhang Bin
Department of Chemistry, School of Science, Tianjin University, Tianjin, China.
Institute of Molecular Plus, Tianjin University, Tianjin, China.
Nat Protoc. 2025 Aug 4. doi: 10.1038/s41596-025-01230-z.
The semi-hydrogenation of alkynes to alkenes, especially acetylene to ethylene, is an essential transformation that delivers raw materials and scaffolds for synthetic industries. Electrocatalytic hydrogenation, which is green and mild, provides an alternative strategy to the conventional hydrogenation process, which relies on high temperature, high pressure and flammable H. This protocol describes an electrocatalytic semi-hydrogenation method to synthesize olefins with water as the hydrogen source under ambient temperature and pressure. Electrocatalytic semi-hydrogenation involves the adsorption and activation of alkynes and the cathodic generation of the active hydrogen (H*) intermediate from water dissociation, followed by the addition of H* to an adsorbed alkyne to yield an alkene. This process is generally assisted by Cu-based electrocatalysts (sulfur-modified Cu and Cu nanoparticles) and commercially available reaction vessels and is performed under a direct-current or constant potential power supply. Here we provide detailed procedures for catalyst design synthesis, alkene electrosynthesis and electrochemical in situ/ex situ spectroscopies for investigating reaction mechanisms. The semi-hydrogenation procedure can be performed within hours; it can also be flexibly adapted to synthetic procedures performed in batch or flow reactors and for various reaction times to meet the adjustable capacity requirements for fine or bulk chemicals. Compared with conventional approaches, the electrocatalytic semi-hydrogenation method eliminates the need for expensive and toxic hydrogenation reagents and conditions with elevated temperature and pressure. Our electrocatalytic semi-hydrogenation strategy has various advantages as a sustainable and alternative method to existing methods, including high alkene selectivity, operational simplicity, substrate universality and easily reproducible functional group compatibility.
炔烃半加氢制烯烃，尤其是乙炔制乙烯，是一种为合成工业提供原材料和骨架的重要转化反应。电催化加氢绿色温和，为依赖高温、高压和易燃氢气的传统加氢工艺提供了一种替代策略。本方案描述了一种在常温常压下以水为氢源电催化半加氢合成烯烃的方法。电催化半加氢包括炔烃的吸附和活化以及水电离阴极产生活性氢（H*）中间体，随后H*加成到吸附的炔烃上生成烯烃。该过程通常由铜基电催化剂（硫改性铜和铜纳米颗粒）和市售反应容器辅助，并在直流或恒电位电源下进行。在此，我们提供了详细的催化剂设计合成、烯烃电合成以及用于研究反应机理的电化学原位/非原位光谱学方法。半加氢过程可在数小时内完成；它还可以灵活地适用于在间歇式或流动反应器中进行的合成过程以及不同的反应时间，以满足精细或大宗化学品的可调产能需求。与传统方法相比，电催化半加氢方法无需昂贵且有毒的加氢试剂以及高温高压条件。作为一种可持续的现有方法替代策略，我们的电催化半加氢策略具有多种优势，包括高烯烃选择性、操作简便、底物通用性以及易于重现的官能团兼容性。
