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

Nowadays, ethanol production from CO 2 hydrogenation has emerged as a viable pathway for CO 2 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 CO 2 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 Co 2+ –O v –Co 2+ (O v: oxygen vacancy), Co–O–K, and Cu + –O–K structures. Notably, as-constructed Cu/CoO x 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 mmol EtOH ·g cat –1 ·h –1 at 260 °C. Based on multiple structural characterizations, spectroscopic analysis, and density functional theory calculations, it was uncovered that defective CoO x and Cu + –O–K structures promoted the generation of formate intermediates during CO 2 hydrogenation, and meanwhile, the effective coadsorption of K + and Cu + stabilized formate intermediates. Accordingly, active K +, Cu + and CoO x species over CuCo-based catalysts exhibited synergistic catalysis, which significantly improved the CH x -HCOO coupling process at K-loaded Cu/CoO x 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 CO 2 hydrogenation.