Cobalt–Nickel Catalysts for Selective Hydrogenation of Carbon Dioxide into Ethanol
journal contributionposted on 12.11.2019, 14:04 by Lingxiang Wang, Shenxian He, Liang Wang, Ye Lei, Xiangju Meng, Feng-Shou Xiao
Selective hydrogenation of CO2 into valuable ethanol proceeds by the coupling of appropriate C1 intermediates to form C2-oxygenates. Matching the different C1 intermediates is crucial for this process but is difficult to control. We found that incorporation of nickel species into the cobalt catalyst could boost the formation of relatively stable *CHx intermediate from CO2 hydrogenation, which significantly avoids an occurrence of methanation. The *CHx species subsequently insert into the *HCOO, another intermediate that is easily formed, to produce C2-oxygenates. Following this pathway, the optimized catalyst, Co0.52Ni0.48AlOx, gives the ethanol yield at 15.8 mmol gcat–1 with selectivity at 85.7% in the CO2 hydrogenation at 200 °C for 12 h, which even outperforms those of noble metal catalysts.