A Multi-Parametric Catalyst Screening for CO2 Hydrogenation to Ethanol

Abstract

The direct hydrogenation of CO2 to higher alcohols has the potential to turn the main contributor of global warming into a valuable feedstock. However, for this technology to become attractive, more efficient and, especially, selective catalysts are required. Here we present a high throughput study on the influence of different promoters on the CO2 hydrogenation performance of Rh−SiO2 catalysts. Fe and K promoters were found to improve ethanol selectivity at the expense of undesired CH4. The best-performing catalyst, with a composition 2 wt.% K, 20 wt.% Fe, and 5 wt.% Rh, displays an EtOH selectivity of 16 % at CO2 conversion level of 18.4 % and CH4 selectivity of 46 %. The combination of different characterization techniques and catalyst screening allowed us to unravel the role of each catalyst component in this complex reaction mechanism.