Concerted Harnessing of Interfacial Concentration Field and Electronic Field for Boosting Electrocatalytic Semi‐Hydrogenation of Alkynol

Electrocatalytic semi-hydrogenation offers a sustainable and atom-economical route for alkynes to alkenes conversion. However, a prevalent activity-selectivity trade-off plagues the electrocatalyst design that relies exclusively on electronic structure tuning. Herein, an interfacial dual-field synergy strategy was proposed for achieving high Faradaic efficiency (FE) and selectivity in electrocatalytic alkynol semi-hydrogenation. The tip-induced accumulation of hydrated K⁺ and the introduction of Pd atoms were verified by theoretical screening as an effective method to acquire the concentration and electronic field synergy. Guided by it, the Cu nanothorns deposited with Pd atomic clusters were well-constructed, which delivered high selectivity of 99% and FE of 96.5% toward alkenol with robust stability at a low potential of -0.18 V versus RHE. Detailed analysis was demonstrated to rationalize the interfacial alkynol and hydrated K⁺ accumulation by concentration field regulation, as well as the electron divergence of Pd^δ+ and Cu^δ ^- atoms with concerted C≡C and H binding on Pd^δ+ sites by electronic field modulation. Benefiting from the interfacial dual-field synergy building a favorable reactant-rich and intermediate-coordinating microenvironment, the origin of dual achievement in both high FE and selectivity was illustrated. Our work provides a technically feasible and economically valuable solution for transcending the activity-selectivity dilemma for electrocatalysis.