Neighboring Cu/Ni sites modulate interfacial electronic structure in ZIF-8-derived N-doped carbon for selective CO2-to-CO electroreduction

Renewable-electricity-driven CO₂-to-CO electroreduction is a promising approach for sustainable carbon utilization, yet efficient CO production requires precise control of interfacial adsorption, proton-coupled electron transfer, and competing hydrogen evolution. Isolated metal centers are often constrained by linear scaling relationships, hindering the simultaneous optimization of CO₂ activation, *COOH formation, and suppression of the hydrogen evolution reaction. Herein, we report an N-doped carbon catalyst derived from zeolitic imidazolate framework-8, containing neighboring Cu/Ni sites that cooperatively regulate the CO₂-to-CO pathway. Aberration-corrected high-angle annular dark-field scanning transmission electron microscopy reveals atomically dispersed metal features and neighboring bright-spot configurations with a projected-separation distribution centered at approximately 2.35 Å, while localized electron energy-loss spectroscopy supports Cu/Ni coexistence within representative neighboring regions. The optimized catalyst achieves a CO Faradaic efficiency of approximately 99% at −0.70 V versus the reversible hydrogen electrode, with a corresponding CO partial current density of 31.78 mA cm⁻², and maintains stable operation for 52.3 h. Post-reaction scanning transmission electron microscopy and X-ray photoelectron spectroscopy further indicate that the atomically dispersed metal features and metal–N coordination environments are largely preserved after long-term electrolysis. Density functional theory calculations based on a representative adjacent Cu/Ni–Nₓ model show that the free-energy change for the potential-determining *COOH formation at the Ni-centered site is 1.08 eV. Electronic-structure analyses further suggest that neighboring Cu modulates the local electronic environment of Ni, contributing to site-differentiated interfacial reactivity. This work establishes a link between neighboring Cu/Ni sites, interfacial electronic modulation, and CO₂-to-CO performance, providing an interface-engineering strategy for selective CO₂ electroreduction. Download: Download high-res image (156KB) Download: Download full-size image