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

Abstract

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.