标题: Enhanced kinetics of CO2 electro-reduction on a hollow gas bubbling electrode in molten ternary carbonates
作者: Gao, MX (Gao, Muxing); Deng, BW (Deng, Bowen); Chen, ZG (Chen, Zhigang); Tao, M (Tao, Meng); Wang, DH (Wang, Dihua)
来源出版物: ELECTROCHEMISTRY COMMUNICATIONS 卷: 100 页: 81-84 DOI: 10.1016/j.elecom.2019.01.026 出版年: MAR 2019
摘要: Electrochemical reduction of CO2 to value-added carbon and oxygen in lithium-containing molten carbonates at 723 K is a promising approach to the efficient utilization of CO2. It was recently reported that the cathodic process in this transformation is controlled by the sluggish diffusion of the generated O(2- )ions. The formation of Li2O on the cathode results in partial cathodic passivation of the cathode. To accelerate the reaction kinetics and also eliminate the concentration polarization of the resulting Li2O, the effect of bubbling CO2 through a hollow electrode was examined in this work using a home-made hollow gas bubbling (HGB) electrode. The localised CO2 bubbling not only accelerates the transport of O(2- )ions by agitating the electrolyte nearby, but the CO2 also reacts with Li2O to form the more soluble Li2CO3. Cyclic voltammetry (CV), linear sweep voltammetry (LSV) and constant current electrolysis were conducted in the melt at 723 K to study the depolarization mechanisms involved in the CO2 bubbling reaction. Using the HGB electrode, the steady-state current density increased from 15.3 mA/cm(2) to similar to 200 mA/cm(2) at a potential of - 2.4 V (vs. Ag/Ag-2 SO4). The HGB electrode effectively improved the cathodic kinetics, which is beneficial for CO2 capture and electrochemical conversion.
作者关键词: CO2 conversion; Molten carbonates; Passivation; Electrode kinetics
地址: [Gao, Muxing; Deng, Bowen; Chen, Zhigang; Wang, Dihua] Wuhan Univ, Sch Resource & Environm Sci, Hubei Int Sci & Technol Cooperat Base Sustainable, Wuhan 430072, Hubei, Peoples R China.
[Tao, Meng] Arizona State Univ, Sch Elect Comp & Energy Engn, Tempe, AZ 85287 USA.
通讯作者地址: Wang, DH (通讯作者)，Wuhan Univ, Sch Resource & Environm Sci, Hubei Int Sci & Technol Cooperat Base Sustainable, Wuhan 430072, Hubei, Peoples R China.
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