Synergistic Surface–Interface Catalysis in Potassium-Loaded Cu/CoOx Catalysts to Boost Ethanol Production from CO2 Hydrogenation

Nowadays, ethanol production from CO2 hydrogenation has emerged as a viable pathway for CO2 capture and efficient utilization. However, catalysts based on nonprecious metals still face significant challenges in achieving high catalytic efficiency for ethanol production. In this study, we constructed K-incorporated CuCo-based catalysts, which were obtained from Cu-Co-Al layered double hydroxide precursors, for efficient CO2 hydrogenation to produce ethanol. It was shown that the incorporation of K into catalysts could finely tune the electronic structures of copper and cobalt species, thereby promoting the formation of substantial surface Co2+-Ov-Co2+ (Ov: oxygen vacancy), Co-O-K, and Cu+-O-K structures. Notably, as-constructed Cu/CoOx catalyst bearing a K loading of 3 wt % achieved an impressively high ethanol selectivity of 38.8% at 200 °C as well as a remarkably high ethanol production rate of 2.76 mmolEtOH·gcat-1·h-1 at 260 °C. Based on multiple structural characterizations, spectroscopic analysis, and density functional theory calculations, it was uncovered that defective CoOx and Cu+-O-K structures promoted the generation of formate intermediates during CO2 hydrogenation, and meanwhile, the effective coadsorption of K+ and Cu+ stabilized formate intermediates. Accordingly, active K+, Cu+ and CoOx species over CuCo-based catalysts exhibited synergistic catalysis, which significantly improved the CHx-HCOO coupling process at K-loaded Cu/CoOx interfaces to boost ethanol production. This study presents a novel surface-interface engineering approach for designing non-noble-metal-based catalysts for efficient ethanol production from CO2 hydrogenation.