Synthesis of ethanol from aryl methyl ether/lignin, CO2 and H2.

Currently, ethanol is produced via hydration of ethene or fermentation of foods. Lignin and CO2 are abundant, cheap and renewable feedstocks. Synthesis of ethanol using the lignin or its derivatives is of great importance, but is a great challenge and has rarely been reported. Herein, we propose a route to synthesize ethanol from CO2, H2, and lignin or various aryl methyl ethers, which can be derived from lignin. The reaction could be effectively conducted using Ru-Co bimetallic catalyst and the TON of ethanol could reach 145. Interestingly, ethanol was the only liquid product when lignin was used. A series of control experiments indicate that ethanol was formed via cleavage of aryl ether bond, reverse water gas shift (RWGS) reaction, and C-C bond formation. This protocol opens a way to produce ethanol using abundant renewable resources.