Ternary Ionic-Liquid-Based Electrolyte Enables Efficient Electro-reduction of CO2 over Bulk Metal Electrodes

Jiahao Yang; Xinchen Kang; Jiapeng Jiao; Xueqing Xing; Yaoyu Yin; Shuaiqiang Jia; Mengen Chu; Shitao Han; Wei Xia; Haihong Wu; Mingyuan He; Buxing Han

doi:10.1021/jacs.3c03259

Ternary Ionic-Liquid-Based Electrolyte Enables Efficient Electro-reduction of CO₂ over Bulk Metal Electrodes

J Am Chem Soc. 2023 May 31;145(21):11512-11517. doi: 10.1021/jacs.3c03259. Epub 2023 May 17.

Authors

Jiahao Yang¹, Xinchen Kang^{2

3}, Jiapeng Jiao¹, Xueqing Xing⁴, Yaoyu Yin^{2

3}, Shuaiqiang Jia¹, Mengen Chu¹, Shitao Han¹, Wei Xia¹, Haihong Wu^{1

5}, Mingyuan He^{1

5}, Buxing Han^{1

2

3

5}

Affiliations

¹ Shanghai Key Laboratory of Green Chemistry and Chemical Processes, School of Chemistry and Molecular Engineering, East China Normal University, Shanghai 200062, China.
² Beijing National Laboratory for Molecular Sciences, Key Laboratory of Colloid and Interface and Thermodynamics, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
³ School of Chemistry, University of Chinese Academy of Sciences, Beijing 100049, China.
⁴ Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China.
⁵ Institute of Eco-Chongming, 20 Cuiniao Road, Chenjia Town, Chongming District, Shanghai 202162, China.

PMID: 37196054
DOI: 10.1021/jacs.3c03259

Abstract

Using bulk metals as catalysts to get high efficiency in electro-reduction of CO₂ is ideal but challenging. Here, we report the coupling of bulk metal electrodes and a ternary ionic-liquid-based electrolyte, 1-butyl-3-methylimidazolium tetrafluoroborate/1-dodecyl-3-methylimidazolium tetrafluoroborate/MeCN to realize highly efficient electro-reduction of CO₂ to CO. Over various bulk metal electrodes, the ternary electrolyte not only increases the current density but also suppresses the hydrogen evolution reaction to obtain a high Faradaic efficiency (FE) toward CO. FE_CO could maintain ∼100% over a wide potential range, and metal electrodes showed very high stability in the ternary electrolyte. It is demonstrated that the aggregation behavior of the ternary electrolyte and the arrangement of two kinds of IL cations with different chain lengths in the electrochemical double layer not only increase the wettability to electrode and CO₂ adsorption but also extend the diffusion channel of H⁺, rendering the high current density and FE_CO.