Bond-Level Dipole Moment Engineering Enables Dual Locking of Lattice Oxygen for Stable CO2-to-Ethylene Electroreduction

Copper-based electrocatalysts are highly promising for CO2-to-ethylene conversion, yet their performance degrades because lattice oxygen is lost and Cu+ is reduced to Cu0 under cathodic conditions. To address this challenge, we employed a bond-level dipole moment engineering strategy to stabilize lattice oxygen in Al-doped Cu2O. The oxophilic Al dopant enables a dual-locking mechanism through direct Al–O anchoring and enhanced neighboring Cu–O interactions by increasing the dipole moment. DFT calculations show that Al incorporation lowers antibonding orbital occupancy in Cu+ 3d–O 2p hybridized states, thereby suppressing lattice oxygen leaching. As a result, Al-Cu2O delivers a C2H4 Faradaic efficiency of 37.0%, compared with 20.5% for pristine Cu2O, and maintains stable operation for 50 h. This work supports bond-level dipole moment as a theoretical descriptor for catalyst stability and provides insights into stabilizing oxygen-containing electrocatalysts.