Synthesis of ethanol via a reaction of dimethyl ether with CO2 and H2

Abstract

Ethanol is currently produced via the catalytic hydration of ethylene or fermentation of foods. The synthesis of ethanol from cheap and renewable CO₂ is of great importance, but the state of the art routes encounter difficulties, especially in reaction selectivity and activity. Here we show a strategy of ethanol synthesis from CO₂, dimethyl ether (DME) and H₂. The reaction can be effectively promoted with a Ru–Co bimetallic catalyst using LiI as a promoter in 1,3-dimethyl-2-imidazolidinone (DMI) solvent. The predominant product of this reaction was ethanol and the selectivity of ethanol in total products could reach 71.7 C-mol%. The selectivity of ethanol in the liquid product could reach 94.1%, which was higher than the reported routes using CO₂/CO. To the best of our knowledge, this is the first work on ethanol synthesis from DME, CO₂ and H₂. The reaction mechanism is discussed based on a series of control experiments.