Regulating the reaction zone of electrochemical CO2 reduction on gas-diffusion electrodes by distinctive hydrophilic-hydrophobic catalyst layers

Rabiee, Hesamoddin ORCID: https://orcid.org/0000-0003-0439-955X and Ge, Lei ORCID: https://orcid.org/0000-0003-2989-0329 and Zhao, Jing and Zhang, Xueqin and Li, Mengran and Hu, Shihu and Smart, Simon and Rufford, Thomas E. and Zhu, Zhonghua and Wang, Hao and Yuan, Zhiguo (2022) Regulating the reaction zone of electrochemical CO2 reduction on gas-diffusion electrodes by distinctive hydrophilic-hydrophobic catalyst layers. Applied Catalysis B: Environmental, 310:121362. pp. 1-11. ISSN 0926-3373


Abstract

Regulating the rational wettability on gas-diffusion electrodes (GDEs) plays a pivotal role to improve the efficiency of CO2RR via fine-tuning the reaction zone and boosting the formation of triple-phase interfaces. Herein, we present a wettability regulation strategy that modulates the triple-phase reaction zone in the catalyst layer of GDEs. This strategy was employed on a flow-through hollow fiber GDE coated with a Bi-embedded catalyst layer. Compared to other ex-situ methods (e.g., adding wetting agents) affecting the bulk of electrocatalysts or catalyst layer, we create distinctive hydrophilic-hydrophobic regions within the catalyst layer. Catalyst layer with hydrophilic-hydrophobic regions outperforms the fully hydrophilic one by facilitating the species transport, boosting triple-phase interface formation, and maximizing the active sites. This regulation strategy showed stable wettability during CO2RR cathodic conditions, evidenced by the direct measurement of penetration depth. The electrode with the regulated wettability exhibited over 80% catalyst utilization and 4 times higher formate partial current density (~150 mA cm−2 with FEformate> 90%) compared to the untreated electrode, outperforming other GDEs employed for CO2RR to formate in the same concentrations of bicarbonate. The finding of this versatile microenvironment regulation strategy can be extended to GDEs used for other gas-phase reactions.


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Item Type: Article (Commonwealth Reporting Category C)
Refereed: Yes
Item Status: Live Archive
Additional Information: Files associated with this item cannot be displayed due to copyright restrictions.
Faculty/School / Institute/Centre: Current - Institute for Advanced Engineering and Space Sciences - Centre for Future Materials (1 Jan 2017 -)
Faculty/School / Institute/Centre: Current - Institute for Advanced Engineering and Space Sciences - Centre for Future Materials (1 Jan 2017 -)
Date Deposited: 09 May 2022 23:38
Last Modified: 09 May 2022 23:38
Uncontrolled Keywords: Electrochemical CO2 reduction; Formate production; Gas-diffusion electrode; Hollow fiber; Microenvironment regulation
Fields of Research (2020): 34 CHEMICAL SCIENCES > 3403 Macromolecular and materials chemistry > 340301 Inorganic materials (incl. nanomaterials)
40 ENGINEERING > 4004 Chemical engineering > 400404 Electrochemical energy storage and conversion
Identification Number or DOI: https://doi.org/10.1016/j.apcatb.2022.121362
URI: http://eprints.usq.edu.au/id/eprint/48189

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