Unveiling subsurface hydrogen inhibition for promoting electrochemical transfer semihydrogenation of alkynes with water

Highly selective electrocatalytic semihydrogenation of alkynes to alkenes with water as the hydrogen source over palladium-based electrocatalysts is significant but remains a great challenge because excessive hydrogenation capacity palladium. Here, we propose that an ideal palladium catalyst should possess weak alkene adsorption and inhibit subsurface formation stimulate high selectivity alkyne semihydrogenation. Therefore, sulfur-modified Pd nanowires (Pd-S NWs) are designedly prepared by solid-solution interface sulfuration method KSCN sulfur source. The introduction S weakens prevents diffusion active (H*) into lattice form unfavorable H*. As result, achieved Pd-S NWs cathode wide substrate scopes, potential-independent up 99% selectivity, good fragile groups compatibility, easily synthesized deuterated alkenes. An adsorbed addition mechanism this reaction proposed. Importantly, easy modification commercial Pd/C in situ SCN? enabling gram-scale synthesis 95% conversion highlights promising potential our method.