Enhanced kinetics of CO                         2                          electro-reduction on a hollow gas bubbling electrode in molten ternary carbonates

Muxing Gao; Bowen Deng; Zhigang Chen; Meng Tao; Dihua Wang

doi:10.1016/j.elecom.2019.01.026

Enhanced kinetics of CO ₂ electro-reduction on a hollow gas bubbling electrode in molten ternary carbonates

Muxing Gao, Bowen Deng, Zhigang Chen, Meng Tao, Dihua Wang

Research output: Contribution to journal › Article › peer-review

18 Scopus citations

Abstract

Electrochemical reduction of CO ₂ to value-added carbon and oxygen in lithium-containing molten carbonates at 723 K is a promising approach to the efficient utilization of CO ₂ . 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 Li ₂ O 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 Li ₂ O, the effect of bubbling CO ₂ through a hollow electrode was examined in this work using a home-made hollow gas bubbling (HGB) electrode. The localised CO ₂ bubbling not only accelerates the transport of O ²⁻ ions by agitating the electrolyte nearby, but the CO ₂ also reacts with Li ₂ O to form the more soluble Li ₂ CO _3. 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 CO ₂ bubbling reaction. Using the HGB electrode, the steady-state current density increased from 15.3 mA/cm ² to ~200 mA/cm ² at a potential of −2.4 V (vs. Ag/Ag ₂ SO ₄ ). The HGB electrode effectively improved the cathodic kinetics, which is beneficial for CO ₂ capture and electrochemical conversion.

Original language	English (US)
Pages (from-to)	81-84
Number of pages	4
Journal	Electrochemistry Communications
Volume	100
DOIs	https://doi.org/10.1016/j.elecom.2019.01.026
State	Published - Mar 2019

Keywords

CO conversion
Electrode kinetics
Molten carbonates
Passivation

ASJC Scopus subject areas

Electrochemistry

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10.1016/j.elecom.2019.01.026

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Enhanced kinetics of CO ₂ electro-reduction on a hollow gas bubbling electrode in molten ternary carbonates . / Gao, Muxing; Deng, Bowen; Chen, Zhigang et al.
In: Electrochemistry Communications, Vol. 100, 03.2019, p. 81-84.

Research output: Contribution to journal › Article › peer-review

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title = " Enhanced kinetics of CO 2 electro-reduction on a hollow gas bubbling electrode in molten ternary carbonates ",

abstract = " Electrochemical reduction of CO 2 to value-added carbon and oxygen in lithium-containing molten carbonates at 723 K is a promising approach to the efficient utilization of CO 2 . 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 Li 2 O 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 Li 2 O, the effect of bubbling CO 2 through a hollow electrode was examined in this work using a home-made hollow gas bubbling (HGB) electrode. The localised CO 2 bubbling not only accelerates the transport of O 2− ions by agitating the electrolyte nearby, but the CO 2 also reacts with Li 2 O to form the more soluble Li 2 CO 3. 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 CO 2 bubbling reaction. Using the HGB electrode, the steady-state current density increased from 15.3 mA/cm 2 to ~200 mA/cm 2 at a potential of −2.4 V (vs. Ag/Ag 2 SO 4 ). The HGB electrode effectively improved the cathodic kinetics, which is beneficial for CO 2 capture and electrochemical conversion.",

keywords = "CO conversion, Electrode kinetics, Molten carbonates, Passivation",

author = "Muxing Gao and Bowen Deng and Zhigang Chen and Meng Tao and Dihua Wang",

note = "Funding Information: This work was funded by National Natural Science Foundation of China ( 21673162 , 51874211 ), the International Science & Technology Cooperation Program of China ( 2015DFA90750 ). Publisher Copyright: {\textcopyright} 2019 The Authors",

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AU - Tao, Meng

AU - Wang, Dihua

N1 - Funding Information: This work was funded by National Natural Science Foundation of China ( 21673162 , 51874211 ), the International Science & Technology Cooperation Program of China ( 2015DFA90750 ). Publisher Copyright: © 2019 The Authors

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N2 - Electrochemical reduction of CO 2 to value-added carbon and oxygen in lithium-containing molten carbonates at 723 K is a promising approach to the efficient utilization of CO 2 . 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 Li 2 O 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 Li 2 O, the effect of bubbling CO 2 through a hollow electrode was examined in this work using a home-made hollow gas bubbling (HGB) electrode. The localised CO 2 bubbling not only accelerates the transport of O 2− ions by agitating the electrolyte nearby, but the CO 2 also reacts with Li 2 O to form the more soluble Li 2 CO 3. 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 CO 2 bubbling reaction. Using the HGB electrode, the steady-state current density increased from 15.3 mA/cm 2 to ~200 mA/cm 2 at a potential of −2.4 V (vs. Ag/Ag 2 SO 4 ). The HGB electrode effectively improved the cathodic kinetics, which is beneficial for CO 2 capture and electrochemical conversion.

AB - Electrochemical reduction of CO 2 to value-added carbon and oxygen in lithium-containing molten carbonates at 723 K is a promising approach to the efficient utilization of CO 2 . 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 Li 2 O 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 Li 2 O, the effect of bubbling CO 2 through a hollow electrode was examined in this work using a home-made hollow gas bubbling (HGB) electrode. The localised CO 2 bubbling not only accelerates the transport of O 2− ions by agitating the electrolyte nearby, but the CO 2 also reacts with Li 2 O to form the more soluble Li 2 CO 3. 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 CO 2 bubbling reaction. Using the HGB electrode, the steady-state current density increased from 15.3 mA/cm 2 to ~200 mA/cm 2 at a potential of −2.4 V (vs. Ag/Ag 2 SO 4 ). The HGB electrode effectively improved the cathodic kinetics, which is beneficial for CO 2 capture and electrochemical conversion.

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