Enrichment of Polarized Alkynes over Negatively Charged Pt for Efficient Electrocatalytic Semihydrogenation

Semihydrogenation of alkynes is a crucial industrial process for the mass production of polymer-grade alkenes and fine chemicals. An electrocatalytic semihydrogenation strategy presents a mild but powerful alternative to conventional processes under critical conditions and yet is suffering from a low catalytic efficiency due to the sacrificed intrinsic activity to depress unwanted overhydrogenation. Here, we report a negatively charged Pt (Ptδ−) induced by coupling with strong electron donator W2C nanoparticles in dual-junction materials to promote the electrocatalytic semihydrogenation of alkynes to alkenes using water as the hydrogen source. The negatively charged surface of Pt metals enables the polarization and unexpected preferential enrichment of alkynes, accelerating the following semihydrogenation process on the real Ptδ−-based electrode. A significantly elevated energy barrier of overhydrogenation from the Ptδ− surface further ensures the semihydrogenation selectivity, breaking the selectivity-activity trade-off for semihydrogenation of a wide scope of alkynes. Moreover, the negatively charged Pt-based electrode as a reusable cathode could exhibit a turnover frequency of 310 h–1 at −0.4 V versus Ag/AgCl, surpassing 6-fold the reported semihydrogenation catalysts with potential advantages for practical applications.