Selenium Vacancy Promotes Transfer Semihydrogenation of Alkynes from Water Electrolysis

Developing an efficient strategy for the highly selective transformation of alkynes to alkenes over a cost-effective catalyst using a cheap and safe hydrogen donor under ambient conditions is markedly desirable. Here self-supported Ni0.85Se nanowires with selenium vacancies (denoted as Ni0.85Se1–x) have been synthesized to enable the transfer semihydrogenation of alkynes with high conversion efficiency and selectivity. Theoretical results demonstrate that the accelerated electron transfer from the catalyst to the alkyne molecules and the much lower activation energy barrier of water electrolysis caused by the Se vacancy are conducive to alkyne semihydrogenation, with up to 99% conversion yield at a lower potential. In addition, the weak adsorption of alkenes and the thermodynamic constraints for overhydrogenation to alkanes are crucial in producing alkenes with 99% selectivity. A broad substrate scope consisting of aryl terminal/internal alkynes and aliphatic alkynes with high conversion yields and selectivity and the facile preparation of deuterated alkenes as versatile building blocks for deuterated synthesis by using D2O highlight the promising potential of our method.