Regulation of the Adsorption Configuration of Interfacial Water to Enhance the Electrocatalytic Semihydrogenation of Alkynols

Electrocatalytic semi-hydrogenation (ECSH) of alkynols offers a highly attractive and sustainable route for producing alkenols. However, achieving efficient alkenol synthesis requires effective suppression of competing side reactions, such as hydrogen evolution reaction (HER) and overhydrogenation. In this work, bimetallic CuBi nanoparticles (NPs) are developed to promote ECSH of alkynols through precise modulation of the catalyst’s interfacial microenvironment. In situ attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy combined with density functional theory (DFT) calculations reveals that incorporating Bi into Cu NPs alters interfacial water adsorption configuration, suppresses HER, enhances reactant 2-methyl-3-butyn-2-ol (MBY) adsorption, and facilitates desorption of the semi-hydrogenation product 2-methyl-3-buten-2-ol (MBE), thereby significantly improving alkynol semi-hydrogenation performance. As a result, CuBi NPs exhibit exceptional electrocatalytic performance in MBY semi-hydrogenation, achieving 100% conversion and 97.7% selectivity at −0.5 VRHE. This work presents a promising strategy for enhancing ECSH of alkynols via rational regulation of the microenvironment at the electrode–electrolyte interface.