Ethanol formation from CO2 hydrogenation at atmospheric pressure using Cu catalysts: Water as a key component

The catalytic conversion of CO2 can reduce its impact in the atmosphere and produce chemicals of industrial interest. Based on this, herein, ethanol formation from CO2 hydrogenation with water was studied. Inspired by CO2 electroreduction results, we show that ethanol can be formed at atmospheric pressure, using metallic Cu catalysts in the CO2 hydrogenation with water steam (CO2 + H2 + H2O) with selectivity of 84% and productivity of ∼2 μmol.gcat–1.h–1 at 190 °C. When only H2O is used (without H2), the same trend was observed. To the best of our knowledge, ethanol is reported for the first time to be synthesized at atmospheric pressure, using only CO2 and water as reactants in a thermocatalytic process. 1H NMR results showed that water (and deuterated water) hydrogenate CO2 to form ethanol. CO-DRIFTS analyses revealed that water enhances the carbon-metal strengthening and this can explain why ethanol production is favored during the CO2 hydrogenation.