In Situ Construction of Co‐Lattice OD‐Cu/Cu ₂ O Heterostructure for Highly Active CO ₂ ‐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.