Direct hydrogenation of CO2 to ethanol at ambient conditions using Cu(I)-MOF in a dielectric barrier discharge plasma reactor

Direct hydrogenation of CO2 to ethanol is a highly economical carbon reduction strategy. However, the CO2 hydrogenation process traditionally requires high temperatures, typically higher than 300 °C, to activate CO2 molecules, which is unfavorable to the formation of ethanol. In contrast, we applied the novel non-thermal plasma to activate CO2 at ambient conditions and a Cu(I)-MOF catalyst to selectively synthesize ethanol for the selective transformation of CO2 into ethanol. The best catalyst, Cu(I)-HKUST-17.5, achieved 41.2% CO2 conversion and up to 62.9% ethanol selectivity under ambient conditions. The control experiments indicated that the Cu(I) sites are key to realizing C–C coupling and ethanol synthesis. An unreported synergistic catalytic mechanism between non thermal plasma and the Cu(I) and Cu(II) sites on the catalyst is proposed based on the DRIFTS analysis. Overall, our work confirms the feasibility of utilizing non thermal plasma assisted catalysis for the selective conversion of CO2 to ethanol under mild conditions.