Lattice Mismatch-Directed Construction of Cu−Co Interfaces for CO2 Hydrogenation to C2+ Alcohols

Abstract

Abstract Cu−Co bimetallic catalysts have demonstrated considerable potential for CO2 hydrogenation to C2+ alcohols. However, their practical application remains constrained by excessive CH4 formation arising from the uncontrolled reduction of Co species under reaction conditions. Herein, we report a semi-encapsulated catalyst architecture constructed through a lattice-mismatching strategy. The lattice mismatch between hexagonal CoO (h-CoO) and ZnO is only 0.18%, whereas that between Cu2O and ZnO reaches 31.4%. When ZnO serves as the seed crystal, Cu2O preferentially nucleates and grows into nanoparticles on the ZnO surface, while h-CoO undergoes epitaxial growth on the exposed ZnO regions, forming a semi-encapsulated configuration in which Cu2O nanoparticles are partially confined by an h-CoO overlayer. The strong lattice matching between h-CoO and ZnO stabilizes Co species in an oxidized state under reaction conditions, thereby suppressing the formation of metallic Co and CH4 production. Meanwhile, the confinement effect imposed by the h-CoO overlayer effectively restricts Cu migration, preserving the Cu−Co interfacial sites that are critical for C−C coupling. As a result, the optimized catalyst achieves a C2+ alcohol selectivity of 63.7% at 300 °C, with an ethanol selectivity of 30.0%, and exhibits no noticeable deactivation over 200 h of continuous operation. This work demonstrates that lattice-matching-directed interfacial engineering represents an effective strategy for simultaneously regulating active-phase stability and metal dispersion, offering new insights into the rational design of catalysts for selective CO2 hydrogenation to C2+ alcohols.