In Situ Construction of Co-Lattice OD-Cu/Cu2O Heterostructure for Highly Active CO2-to-Ethylene Conversion via Strong Additive-Metal Oxide Interaction

Electrochemical reconstruction of electrocatalysts is critical to their practical performances. However, the relevant influencing factors for the evolution process are still rare, restricting the design of high-performance electrocatalysts. Herein, using acidic CO 2 electroreduction reaction (CRR) over Cu 2 O as a model system, we systemically studied how organic additives regulate the reconstruction of high-valent Cu species and the CRR mechanism. Theoretical calculations reveal the relationship between additive physicochemical properties and Cu 2 O. Notably, in situ characterization reveals that DMSO strongly interacts with the catalyst, partially reducing Cu 2 O to form a Co-lattice OD-Cu/Cu 2 O heterostructure with interfacial Cu atoms belong to both Cu 2 O and Cu lattices and exhibits an intermediate valence state. Based on the Co-lattice OD-Cu/Cu 2 O, the Faradaic efficiency (FE) of C 2 H 4 was up to 67.5% at −1.5 V vs. RHE in H 2 SO 4 & Li 2 SO 4 electrolyte with a low FE H2 of 16.8%. Moreover, the combination achieves a stability of over 100 h in membrane electrode assembly (MEA) electrolyzes. Simulations uncover that the DMSO-modified Co-lattice OD-Cu/Cu 2 O optimizes *CO adsorption, lowers C–C coupling barriers and promote the generation of C 2 H 4 . Meanwhile, DMSO spontaneously adsorbs on the catalyst surface and effectively inhibits HER. This work deepens the understanding of electrocatalyst reconstruction behavior and contributes to the development of efficient electrocatalytic systems.