Effect of cu content on Ce-doping CuO/ZrO2 catalysts for low-temperature hydrogenation of dimethyl oxalate to ethanol

In order to solve the Cu sintering in dimethyl oxalate (DMO) hydrogenation to ethanol, the reaction temperature should be kept at a low value, however, which is unable to show excellent catalytic performance. Herein, the reaction temperature decreased significantly from above 260 to 220 degrees C over Ce-doping Cu/ZrO2 catalyst, which retained high catalytic efficiency with little influence on the catalyst structure after 96 h on stream. Besides, the structure and performance were changed greatly by adjusting the Cu content. For example, the ethanol selectivity can reach 96.1% based on the 100% conversion of DMO over Ce-doping Cu/ZrO2 catalysts with 40% content of Cu. Based on systematic characterization, the catalyst possessed higher exposed Cu surface area along with the proper amount of medium acidic sites, avoiding the strong ones that could bring about a series of by-products. As a result, the formed synergistic effects between Cu sites and medium acidic sites provided the active sites with high efficiency for ethanol synthesis.

Automated summary

The addition of cerium to Cu/ZrO2 catalyst can effectively solve the issue of Cu sintering in dimethyl oxalate (DMO) hydrogenation to ethanol, while adjusting the copper content can lead to higher catalytic activity and ethanol selectivity. The catalyst with synergistic effects between copper sites and medium acidic sites offers efficient active sites for ethanol synthesis.