Mesoporous Cu Nanoplates with Exposed Cu+ Sites for Efficient Electrocatalytic Transfer Semi‐Hydrogenation of Alkynes

Electrocatalytic transfer alkyne semi‐hydrogenation with H2O as hydrogen source is industrially promising for selective electrosynthesis of high value‐added alkenes while inhibiting byproduct alkanes. Although great achievements, their development has remarkably restricted by designing atomically sophisticated electrocatalysts. Here, we reported single‐crystalline mesoporous copper nanoplates (meso‐Cu PLs) as a robust yet highly efficient electrocatalyst for selective alkene electrosynthesis from transfer semi‐hydrogenation reaction of alkyne in H2O. Anisotropic meso‐Cu PLs were prepared through a facile epitaxial growth strategy with functional C22H45N(CH3)2‐C3H6‐SH as concurrent mesopore‐forming and structure‐controlled surfactant. Different to nonporous Cu counterparts with flat surface, meso‐Cu PLs exposed abundant Cu+ sites, which not only stabilized active H* radicals from electrocatalytic H2O splitting without coupling into molecular H2 but also accelerated kinetically the desorption of semi‐hydrogenated alkenes. With 4‐aminophenylacetylene (4‐AP) as the substrate, anisotropic meso‐Cu PLs delivered superior electrocatalytic transfer semi‐hydrogenation performance with up to 99% of 4‐aminostyrene (4‐AS) selectivity and 100% of 4‐AP conversion as well as good cycle stability (6 cycles). Meanwhile, meso‐Cu PLs were electrocatalytically applicable for transfer semi‐hydrogenation of various alkynes. This work paved an alternative paradigm for designing robust mesoporous metal electrocatalysts with structurally functional metal sites applied in the selective electrosynthesis of industrially value‐added chemicals in H2O.