Electrochemical CO ₂ Reduction on Janus Dual‐Atom Catalysts: Critical Role of Oxygen Coordination and an Effective Descriptor

Abstract Dual‐atom catalysts (DACs) embedded in nitrogen‐doped graphene have been widely studied for electrochemical CO ₂ reduction (CO ₂ R), primarily yielding CO. However, achieving selectivity for C1 hydrocarbons remains challenging. Here, 32 Janus DACs (J‐M'M) are designed and investigated for CO ₂ R using density functional theory (DFT) calculations, identifying 13 capable of producing methanol and methane. Notably, J‐FeCo and J‐CoNi exhibit favorable limiting potentials (−0.38 and −0.45 V vs. RHE) for CH ₃ OH and CH ₄ production, respectively, based on constant‐potential calculations. Compared to normal DACs (N‐M'M), Janus DACs demonstrate enhanced initial CO ₂ hydrogenation and stronger CO adsorption. Oxygen coordination in J‐FeCo and J‐CoNi induces a downshift/upshift of majority‐/minority‐spin energy levels of d _z2 , d _yz , and d _xz orbitals toward the Fermi level relative to N‐FeCo and N‐CoNi, strengthening the bonding state and weakening the antibonding state, thereby improving CO adsorption. Furthermore, an effective descriptor based on atomic features is identified to evaluate *CO binding strength. This work highlights the critical role of partial oxygen coordination in DACs for C1 hydrocarbons production and proposes a robust descriptor to guide the design of related catalysts.