Electrochemically Mediated Direct CO₂ Capture by a Stackable Bipolar Cell

Abstract

The unprecedented increase in atmospheric CO 2 concentration calls for effective carbon capture technologies. With distributed sources contributing to about half of the overall emission, CO 2 capture from the atmosphere [direct air capture, (DAC)] is more relevant than ever. Herein, an electrochemically mediated DAC system is reported which utilizes affinity of redox-active quinone moieties towards CO 2 molecules, and unlike incumbent chemisorption technologies which require temperature or pH swing, relies solely on the electrochemical voltage for CO 2 capture and release. The design and operation of a DAC system is demonstrated with stackable bipolar cells using quinone chemistry. Specifically, poly(vinylanthraquinone) (PVAQ) nega-tive electrode undergoes a two-electron reduction reaction and reversibly complexes with CO 2 , leading to CO 2 sequestration from the feed stream. The subsequent PVAQ oxidation, conversely, results in release of CO 2 . The performance of both small-and meso-scale cells for DAC are evaluated with feed CO 2 concentrations as low as 400 ppm (0.04 %), and energy consumption is demonstrated as low as 113 kJ per mole of CO 2 captured. Notably, the bipolar cell construct is modular and expandable, equally suitable for small and large plants. Moving forward, this work presents a viable and highly customizable electrochemical method for DAC.

Direct Electrochemical CO2 Capture Using Substituted Anthraquinones in Homogeneous Solutions: A Joint Experimental and Theoretical Study

“… 28 The same group also developed several prototype cells for direct air capture of CO 2 based on AQ polymers. 29 − 31 It has been reported that oxygen (O 2 ) binding and electrochemical O 2 reduction by these AQ-polymers are crucial side-reactions to be considered. 29 , 32 Very recently, Bui et al investigated the impact of multiple substitutions involving several AQ derivatives with CV and related their findings regarding electrochemical potentials with results obtained via density functional theory (DFT) calculations.…”

Challenges and opportunities in continuous flow processes for electrochemically mediated carbon capture

“…Other electrogenerated nucleophiles based on bipyridine and disulfide chemistries have also been explored ( Ishida et al., 1994 ; Ranjan et al., 2015 ; Singh et al., 2017 ). Whereas reports on proof-of-concept EMCC with redox-active organic carriers are primarily batch processes ( Hemmatifar et al., 2022 ; Liu et al., 2020a , 2020b ; Scovazzo et al., 2003 ; Voskian and Hatton, 2019 ) or supported liquid membranes ( Gurkan et al., 2015 ), the first flow-based prototype was demonstrated recently ( Diederichsen et al., 2022 ). In that study, a naphthoquinone derivative was synthesized, which is a liquid at room temperature (“liquid quinone”).…”

The cost of direct air capture and storage: the impact of technological learning, regional diversity, and policy.

“…For example, the recent work by the Hatton group demonstrates a technology that could use much less energy. 64,65 However, there is not enough published data and the technology readiness level is too low to perform an accurate cost assessment, and hence this technology improvement is not considered for analysis in this work.…”