Abstract
The catalytic hydrogenation of CO2 to C2+ products presents a promising way for converting captured carbon dioxide into renewable fuels and chemical feedstocks, yet remains challenging due to the complexity of the reaction network and the limited understanding of structure–performance relationships. In this work, a series of LaCuxFe1–xO3 perovskite catalysts were investigated for CO2 hydrogenation, focusing on ethanol and higher hydrocarbons production. The Cu–Fe perovskite structure offered tunable redox behavior and surface basicity, key parameters for CO2 activation and C–C bond formation. In addition, the role of K promotion was systematically explored to assess its impact on product distribution, surface basicity, and CO adsorption behavior. The catalyst with a Cu:Fe ratio of 0.2:0.8 exhibited the highest selectivity toward C2+ products, while its further promotion with 0.5 wt.% K enhanced both ethanol selectivity (5.5%) and hydrocarbon selectivity (36.1%) at 250 °C and 30 bar, outperforming both the unpromoted catalyst and the catalysts with higher K loading. Operando DRIFTS analysis provided information on the evolution of surface intermediates under reaction conditions, revealing the presence of carbonates, formates, Cu0–CO, and CHx species. The K-promoted catalyst showed increased stability and persistence of CO2-derived intermediates together with enhanced formation of hydrogenated surface species, consistent with its improved C2+ selectivity. A CFD model was also developed that successfully reproduced the observed trends within the studied experimental window. This study provides valuable design insights for perovskite-based catalysts aimed at efficient CO2-to-C2+ conversion.