Direct air capture of CO<inf>2</inf>via cyclic viologen electrocatalysis

Liu, S; Zhang, J; Li, F; Edwards, JP; Xiao, YC; Kim, D; Papangelakis, P; Kim, J; Elder, D; De Luna, P; Fan, M; Lee, G; Miao, RK; Ghosh, T; Yan, Y; Chen, Y; Zhao, Y; Guo, Z; Tian, C; Li, P; Xu, Y; Sargent, EH; Sinton, D

Direct air capture of CO<inf>2</inf>via cyclic viologen electrocatalysis

Liu, S Zhang, J

Li, F Edwards, JP Xiao, YC Kim, D Papangelakis, P Kim, J Elder, D De Luna, P Fan, M Lee, G Miao, RK Ghosh, T Yan, Y Chen, Y Zhao, Y Guo, Z Tian, C Li, P Xu, Y Sargent, EH Sinton, D

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Publisher:: ROYAL SOC CHEMISTRY
Publication Type:: Journal Article
Citation:: Energy and Environmental Science, 2024, 17, (3), pp. 1266-1278
Issue Date:: 2024-01-10

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Field	Value	Language
dc.contributor.author	Liu, S
dc.contributor.author	Zhang, J https://orcid.org/0000-0001-5476-0134
dc.contributor.author	Li, F
dc.contributor.author	Edwards, JP
dc.contributor.author	Xiao, YC
dc.contributor.author	Kim, D
dc.contributor.author	Papangelakis, P
dc.contributor.author	Kim, J
dc.contributor.author	Elder, D
dc.contributor.author	De Luna, P
dc.contributor.author	Fan, M
dc.contributor.author	Lee, G
dc.contributor.author	Miao, RK
dc.contributor.author	Ghosh, T
dc.contributor.author	Yan, Y
dc.contributor.author	Chen, Y
dc.contributor.author	Zhao, Y
dc.contributor.author	Guo, Z
dc.contributor.author	Tian, C
dc.contributor.author	Li, P
dc.contributor.author	Xu, Y
dc.contributor.author	Sargent, EH
dc.contributor.author	Sinton, D
dc.date.accessioned	2025-02-21T00:33:24Z
dc.date.available	2025-02-21T00:33:24Z
dc.date.issued	2024-01-10
dc.identifier.citation	Energy and Environmental Science, 2024, 17, (3), pp. 1266-1278
dc.identifier.issn	1754-5692
dc.identifier.issn	1754-5706
dc.identifier.uri	http://hdl.handle.net/10453/185239
dc.description.abstract	Electrochemical direct air capture (DAC) can leverage renewable electricity to reduce atmospheric CO2 levels via energy-efficient organic redox couples. However, current organic systems are threatened by oxidative degradation when explosed to air. In this work, we propose an electrochemical process to regenerate hydroxide absorbents via cyclic viologen electrocatalysis (CVE). This strategy isolates the redox-active viologens from the alkaline absorbents to avoid oxidative degradation and vaporization loss. Tuning the viologen substituent is needed to facilitate fast reaction kinetics in the electric fields present under reductive and oxidative environments. We show that di-polar viologens, which contain both positively and negatively charged groups, can overcome electric field repulsion during reduction and oxidation. We demonstrate a minimum work of 0.82 GJ per tCO2, calculated based on the cyclic voltammetry redox potentials, and a work as low as 3.8 GJ per tCO2 in a practical two-electrolyser CVE configuration with over 200 hours of stable operation.
dc.language	English
dc.publisher	ROYAL SOC CHEMISTRY
dc.relation.ispartof	Energy and Environmental Science
dc.relation.isbasedon	10.1039/d3ee03024e
dc.rights	info:eu-repo/semantics/closedAccess
dc.subject.classification	Energy
dc.title	Direct air capture of CO<inf>2</inf>via cyclic viologen electrocatalysis
dc.type	Journal Article
utslib.citation.volume	17
pubs.organisational-group	University of Technology Sydney
pubs.organisational-group	University of Technology Sydney/Faculty of Science
pubs.organisational-group	University of Technology Sydney/Faculty of Science/School of Mathematical and Physical Sciences
utslib.copyright.status	closed_access	*
dc.date.updated	2025-02-21T00:33:22Z
pubs.issue	3
pubs.publication-status	Published
pubs.volume	17
utslib.citation.issue	3

Abstract:

Electrochemical direct air capture (DAC) can leverage renewable electricity to reduce atmospheric CO2 levels via energy-efficient organic redox couples. However, current organic systems are threatened by oxidative degradation when explosed to air. In this work, we propose an electrochemical process to regenerate hydroxide absorbents via cyclic viologen electrocatalysis (CVE). This strategy isolates the redox-active viologens from the alkaline absorbents to avoid oxidative degradation and vaporization loss. Tuning the viologen substituent is needed to facilitate fast reaction kinetics in the electric fields present under reductive and oxidative environments. We show that di-polar viologens, which contain both positively and negatively charged groups, can overcome electric field repulsion during reduction and oxidation. We demonstrate a minimum work of 0.82 GJ per tCO2, calculated based on the cyclic voltammetry redox potentials, and a work as low as 3.8 GJ per tCO2 in a practical two-electrolyser CVE configuration with over 200 hours of stable operation.

Please use this identifier to cite or link to this item:

http://hdl.handle.net/10453/185239