Catalytic hydrogenation of CO2 to produce lower alcohols and ether over Co‐Cu‐Zn‐Al catalyst

In this work, Cu‐Co‐Zn‐Al catalysts were prepared by synchronous aging coprecipitation method for direct hydrogenation of CO2 to lower alcohols and ether. The catalysts were characterized by N2 phyhsical adsorption, ICP‐OES, TEM, SEM, XRD, EDX, and XPS. Results showed that the particle size of catalysts ranged from 8.6 to 10.6 nm, indicating that higher reduction temperature resulted in the aggregation of the metal oxide particles. The sheet‐like morphology of catalyst Cu‐Co‐Zn‐Al‐500 is beneficial to expose more active sites. During the reduction process, Co3O4 was reduced to CoO and Co, and CuO was reduced to metallic Cu. Moreover, catalytic performance evaluation results showed that under the reaction temperature of 200°C and reaction time of 10 h, the total carbon formation rate of the liquid product reached 116 C μmol·gcat–1·h–1, with the corresponding yields of methanol, ethanol, propanol, and diisopropyl ether were 31, 41, 12, and 32 C μmol·gcat–1·h–1, respectively. Mechanism study suggested that, Cu played the role of activating the C=O bond of CO2 to form intermediates, Co2+ and Co0 played an important role for C‐C coupling in the reaction, ZnO improved the dispersion and stability of Cu, and Al2O3 as a support played a role in promoting methanol synthesis and alcohol dehydration to produce diisopropyl ether due to its strong Lewis acidity. © 2021 Society of Chemical Industry and John Wiley & Sons, Ltd.