Stabilizing Cu+ Sites at Cu2O(111)-ZrO2 Heterointerfaces for Durable and Selective CO2-to-C2H4 Electroreduction.

Although Cu2O(111) is thermodynamically favorable for CO2 electroreduction, ethylene production is limited by insufficient Cu+ stabilization, leading to modest selectivity and durability. Herein, we report an interfacial engineering strategy to construct nanoscale-coupled Cu2O-ZrO2 heterointerfaces that stabilize Cu+ and promote C-C coupling. Using a zirconium-based metal-organic framework as a confined-conversion template, uniformly dispersed Cu2O(111)-ZrO2 interfaces are generated within a conductive porous carbon matrix (CuZr@C). CuZr@C delivers FEC2H4 = 72.1% at jC2H4 = 39.0 mA cm-2 (-1.3 V vs RHE) in an H cell with >70% retention after 120 h and jC2H4 = 101.6 mA cm-2 in a flow cell. Operando X-ray absorption spectroscopy and Raman confirm Cu+ stabilization and high local CO coverage at the heterointerface. Density functional theory reveals a reduced free-energy barrier of 0.68 eV for the rate-determining *OCCO → *OCCHO step, establishing Cu2O(111)-based oxide heterointerfaces as effective platforms for durable and selective CO2RR to multicarbon products.