p‐Block Antimony Single‐Atom Tuned Copper Sites for Boosting Electrocatalytic Semi‐Hydrogenation of 2‐methyl‐3‐butyn‐2‐ol

and a Faraday efficiency (FE) of 98%. Moreover, they maintain an FE above 80% across a broad potential window, outperforming previously reported catalysts. In situ electrochemical studies combined with theory calculations reveal that Sb single atoms can not only hamper the competing hydrogen evolution reaction by reconstructing a connected hydrogen-bond network but also optimize the adsorption/desorption energetics of intermediates on Cu sites, thereby accelerating the conversion of MBY to MBE. Finally, a coupled system was designed to simultaneously realize the electrochemical semi-hydrogenation of MBY and the oxidation of polyethylene terephthalate to produce MBE and formic acid, showing a lower potential at the same current density than that of coupled with anodic oxygen evolution, in an economical manner.