Switching CO2 Electroreduction toward C2+ Products and CH4 by Regulating the Dimerization and Protonation in Platinum/Copper Catalysts

Abstract Copper (Cu)‐based catalysts exhibit distinctive performance in the electrochemical CO 2 reduction reaction (CO 2 RR) with complex mechanism and sophisticated types of products. The management of key intermediates *CO and *H is a necessary factor for achieving high product selectivity, but lack of efficient and versatile strategies. Herein, we designed Pt modified Cu catalysts to effectively modulate the competitive coverage of those intermediates. The Pt single‐atoms and Pt nanoparticles modified Cu catalysts (denoted as Cu‐Pt 1 and Cu‐Pt NPs ) precisely regulated the protonation and dimerization, with the faradaic efficiency (FE) of C 2+ products up to 70.4 % and the FE of CH 4 reaching 57.7 %, respectively. CO stripping experiments reveal that Pt 1 sites could enhance the adsorption of *CO, while Pt NPs exhibit *CO tolerance for H 2 O dissociation. In situ spectroscopic results further confirms that high coverage of *CO is achieved on Cu‐Pt 1 , while *CHO on Cu‐Pt NPs might generate by additional water dissociation. As elucidated by theoretical studies, the interfacial sites of Cu‐Pt 1 would favor the *CO coverage promoting the evolution of *OCCO for C 2+ products while Pt NPs supplementarily accelerate H 2 O dissociation achieving *CHO for CH 4 . This work provides insights for efficient and targeted CO 2 conversion by atomically design of active sites with engineered key intermediates coverage.