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

Abstract

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.