Alkali Cation Inhibition of Imidazolium-Mediated Electrochemical CO2 Reduction on Silver

被引：0

作者：

Nkurunziza, Francois ^{[1
]}

Dongare, Saudagar ^{[2
]}

Chatterjee, Soumya ^{[3
]}

Shah, Bhavi ^{[1
]}

Gautam, Manu ^{[1
]}

Muchharla, Baleeswaraiah ^{[4
]}

Kumar, Bijandra ^{[4
]}

Janik, Michael J. ^{[3
]}

Gurkan, Burcu ^{[2
]}

Sacci, Robert L. ^{[5
]}

Spurgeon, Joshua M. ^{[1
]}

机构：

[1] Univ Louisville, Conn Ctr Renewable Energy Res, Louisville, KY 40292 USA

[2] Case Western Reserve Univ, Dept Chem & Biomol Engn, Cleveland, OH 44106 USA

[3] Penn State Univ, Dept Chem Engn, University Pk, PA 16802 USA

[4] Elizabeth City State Univ, Dept Math Comp Sci & Engn Technol, Elizabeth City, NC 27909 USA

[5] Oak Ridge Natl Lab, Chem Sci Div, Oak Ridge, TN 37831 USA

来源：

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY | 2025年 / 147卷 / 09期

关键词：

HYDROGEN EVOLUTION REACTION; INITIO MOLECULAR-DYNAMICS; IONIC LIQUID; ELECTROCATALYTIC REDUCTION; CARBON-DIOXIDE; METAL CATIONS; ELECTROREDUCTION; TRANSITION; ELECTRODE; INSIGHTS;

D O I：

10.1021/jacs.4c16635

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

Imidazolium-based ionic liquids have led to enhanced CO2 electroreduction activity due to cation effects at the cathode surface, stabilizing the reaction intermediates and decreasing the activation energy. In aqueous media, alkali cations are also known to improve CO2 reduction activity on metals such as Ag, with the enhancement attributed to electrical double layer effects and trending with the size of the alkali cation. However, the effect of a mixed catholyte solution of alkali cations in the presence of an imidazolium-based ionic liquid has not been well-explored. Herein, 1-ethyl-3-methylimidazolium tetrafluoroborate, [EMIM][BF4], in water was investigated with alkali salts to unravel the interaction effects for CO2 electroreduction on Ag. Although both [EMIM]+ and alkali cations have individually improved CO2 to CO conversion on Ag in water, electrochemical results showed that alkali cations hindered imidazolium-mediated CO2 electroreduction in most conditions. Li+, in particular, was sharply inhibitory compared to other alkali cations and strongly redirected the selectivity to hydrogen evolution. The nature of the alkali cation inhibition was investigated with spectroscopic techniques, including in situ surface-enhanced Raman spectroscopy (SERS) and dynamic electrochemical impedance spectroscopy (DEIS). Along with computational insights from density functional theory (DFT), the electrochemical and spectroscopic data suggest that alkali cations inhibit [EMIM]-mediated CO2 reduction by competing for surface adsorption sites, preventing the potential-dependent structural reorientation of imidazolium, and promoting hydrogen evolution by bringing solvated water to the cathode surface.

引用

页码：7564 / 7577

页数：14