Cu₃N/Cu heterostructures with interfacial electronic modulation for enhanced CO₂ adsorption and efficient CC coupling...

Electrocatalytic CO₂ reduction to multi‑carbon products offers a sustainable route to fuels and chemicals, yet suffers from sluggish CC coupling and competing hydrogen evolution. Here, we report a rationally engineered Cu₃N/Cu@C heterostructure catalyst that delivers markedly enhanced CO₂ electroreduction performance. The optimized catalyst achieves a 65.3% Faradaic efficiency toward multi‑carbon products and a half-cell energy efficiency of 35.3% at -1.1 V versus reversible hydrogen electrode. Combined in situ attenuated total reflectance surface enhanced infrared absorption spectroscopy and density functional theory calculations reveal that interfacial charge transfer at the Cu₃N/Cu junction modulates the electronic structure of Cu sites, elevates local pH, strengthens CO₂ adsorption and activation, and suppresses hydrogen evolution. Importantly, the tailored interface facilitates asymmetric CC coupling between *CO and *COH intermediates, stabilizing the key *OCCOH species and accelerating multi‑carbon products formation. This work underscores heterointerface engineering as a powerful strategy to control reaction microenvironments and CC coupling pathways, guiding the development of high-performance copper-based CO₂ reduction reaction catalysts.