(558ax) Carbon Dioxide Activation and Electroreduction in Ionic Liquids Systems

Authors: 
Zhang, S., Beijing Key Laboratory of Ionic Liquids Clean Process,CAS Key Labroratory of Green Process and Engineering, Institute of Process Engineering, Chinese Academy of Sciences
The increased concentration of carbon dioxide (CO2) emission from fossil fuel has resulted in serious environmental issues, such as global warming[1]. The electrochemical conversion of CO2 into chemicals (Formic acid, oxalic acid, carbon monoxide, and so on) is a promising approach due to its mild reaction conditions and easy implementation. However, the lower solubility of CO2 and lower catalytic performance in aqueous solution lead to an inefficient CO2 electroreduction. Recently, ionic liquids (ILs) have been proven to be functional media for CO2 electrochemical reaction because of their unique physico-chemical properties, like good conductivity, strong electrostatic field, peculiar micro environment and high solubility for CO2 [2].

Recently, we found that high efficiency of CO2 capture and conversion is achieved via an ionic microhabitat (IMH) in the novel IL (such as [Bmim][124Triz]) reaction system, which means the nanoscale aggregates and chemical interaction in the ion of [124Triz]-CO2- result in a superior solubility of CO2 under ambient conditions. More notably, it shows that the stable CO2 molecule is changed to a bent form with a net negative charge (0.546 e) in the [124Triz]-CO2- ion. In addition, the IMH provides a facile route for the transferring of the activated CO2- to the cathode surface, then improves the current density and Faradaic efficiency of CO2 electroreduction. Based on the above principle, we develpoed a series ionic liquids and electro-reduce CO2 to be formic acid, oxalic acid, carbon monoxide with high efficiency[3-5]. Moreover, a continuous device with volume of 1 liter for electrochemical conversion of CO2 to carbon monoxide in ionic liquids is set up, and the scale up mechanism are investigated. This work will provide a promising route for the electrochemical conversion of carbon dioxide to chemicals.

References

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