Cross-Scale Construction of Lattice-Confined Sb Single Atoms in Single-Crystal Cu2O for Highly Active Electrochemical CO2 Reduction to C2+ Products

Abstract Converting CO2 into multi-carbon compounds is usually plagued by the complex reaction pathway and unsatisfactory durability of catalysts. Here, a specific Sb single atom confined in the lattice of the single-crystal Cu2O catalyst (Sb/Cu2O-2) is constructed via a cross-scale construction approach. The Faradaic efficiency of Sb/Cu2O-2 for electrochemical CO2 reduction to C2+ products could achieve 85.5% under the industrial current density of 300 mA cm–2. In situ Raman combined with density functional theory calculations reveal that the lattice-confined Sb single atom shifts the d-band center of the Cu atom from –2.21 to –2.06 eV, largely strengthening the *CO intermediate adsorption, and then it promotes the protonation of *CO. Additionally, the lattice-confined Sb single atom, as the active site, also decreases the energy barrier for C–C coupling, effectively accelerating the CO2 reduction kinetics. Moreover, Sb/Cu2O-2 exhibits long-term durability up to 100 h under –0.55 V (vs. RHE) due to the well-defined single-crystal Cu2O structure and lattice-confined effect. This work provides a catalyst with high performance for electrochemical CO2 reduction, which is essential for the construction of functional catalysts.