Bimetallic PdCu nanohybrid sheets for enhanced electrocatalytic selective semi-hydrogenation of alkynols

The selective semi‑hydrogenation of alkynols to alkenols is crucial in pharmaceutical and fine chemical industries, yet hindered by inefficient thermocatalytic processes and over‑hydrogenation on Pd-based catalysts. Herein, we report a palladium‑copper bimetallic nanohybrid sheet catalyst (PdCu NHSs/NF) that enables efficient electrocatalytic alkynol semi‑hydrogenation (ECSH) using water as the proton source. For 1,4-butynediol (BYD), PdCu NHSs/NF achieves 99.8 % conversion within only 1 h, and 96.4 % selectivity, 95.2 % Faradaic efficiency at a low potential of −0.2  V vs. RHE, while maintaining stability over 10 cycles and broad substrate applicability. In situ EIS and spectroscopic studies revealed that the PdCu bimetallic interface enhances mass transport and reaction kinetics, enabling selective BED formation without over‑hydrogenation. DFT calculations demonstrated the cooperative effect between Pd and Cu active sites optimized the adsorption/desorption energetics, balancing the competition between HER and ECSH. This work provides critical mechanistic insights for designing advanced bimetallic catalysts in selective semi‑hydrogenation.