CO2-Promoted Hydrogenation of Sodium Acetate to Ethanol Over CoAlPt Catalyst: Toward Biomass Valorization

Herein, we present a concept for CO 2 -assisted direct aqueous-phase hydrogenation of sodium acetate to ethanol, offering a salt-tolerant approach that circumvents energy-intensive acidification and simplifies biomass valorization. The reaction was performed over highly dispersed Pt on the CoAlPt (CAP) catalyst, which improves H 2 activation and drives hydrogen spillover, thereby increasing the reactive surface hydrogen species while mitigating excessively strong H adsorption that suppresses activity under alkaline conditions. The CAP catalyst achieved 90.88% ethanol selectivity with a productivity of 3.63 mmol·g −1 ·h −1 at 180°C without CO 2 addition. Introducing CO 2 (0.1 MPa) increased ethanol productivity to 4.92 mmol·g −1 ·h −1 by converting OH − to HCO 3 − and shifting acetate speciation toward molecular acetic acid, which is more readily hydrogenated. The results obtained in this concept study highlight the potential of using CO 2 as a promoter for direct acetate hydrogenation towards a sustainable strategy for converting acetate-rich aqueous streams to ethanol and other value-added products. Graphical CoAlPt (CAP) catalyst enables an efficient aqueous-phase hydrogenation of acetate to ethanol with 90.88% selectivity. Introducing a controlled amount of CO 2 led to a two-way synergistic promotion between acetate and CO 2 hydrogenation, where balanced OH − /HCO 3 − species further enhance ethanol and methane formation.