Ternary Ionic-Liquid-Based Electrolyte Enables Efficient Electro-reduction of CO<sub>2</sub> over Bulk Metal Electrodes

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

doi:10.1021/jacs.3c03259

Cited by 28 publications

(12 citation statements)

References 41 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Molecular-level electrolyte design holds great promise as a strategy for improving the selectivity, efficiency, and stability of electrochemical processes. − This is because of the recognized importance of fundamental, intermolecular interactions in governing the structure of the electrochemical double layer and the reaction-diffusion region near electrodes in which electrochemical and electrocatalytic processes take place. , Modifications to the structure and composition of these critical microenvironments have been demonstrated to result in dramatic changes in chemical reaction outcomes, particularly in the arena of electrosynthetic work …”

Section: Introductionmentioning

confidence: 99%

Mechanistic Basis of Conductivity in Carbon Dioxide-Expanded Electrolytes: A Joint Experimental–Theoretical Study

Nilles,

Borkowski,

Bartlett

et al. 2024

J. Am. Chem. Soc.

View full text Add to dashboard Cite

Electrolyte conductivity contributes to the efficiency of devices for electrochemical conversion of carbon dioxide (CO2) into useful chemicals, but the effect of the dissolution of CO2 gas on conductivity has received little attention. Here, we report a joint experimental–theoretical study of the properties of acetonitrile-based CO2-expanded electrolytes (CXEs) that contain high concentrations of CO2 (up to 12 M), achieved by CO2 pressurization. Cyclic voltammetry data and paired simulations show that high concentrations of dissolved CO2 do not impede the kinetics of outer-sphere electron transfer but decrease the solution conductivity at higher pressures. In contrast with conventional behaviors, Jones reactor-based measurements of conductivity show a nonmonotonic dependence on CO2 pressure: a plateau region of constant conductivity up to ca. 4 M CO2 and a region showing reduced conductivity at higher [CO2]. Molecular dynamics simulations reveal that while the intrinsic ionic strength decreases as [CO2] increases, there is a concomitant increase in ionic mobility upon CO2 addition that contributes to stable solution conductivities up to 4 M CO2. Taken together, these results shed light on the mechanisms underpinning electrolyte conductivity in the presence of CO2 and reveal that the dissolution of CO2, although nonpolar by nature, can be leveraged to improve mass transport rates, a result of fundamental and practical significance that could impact the design of next-generation systems for CO2 conversion. Additionally, these results show that conditions in which ample CO2 is available at the electrode surface are achievable without sacrificing the conductivity needed to reach high electrocatalytic currents.

show abstract

Section: Introductionmentioning

confidence: 99%

Mechanistic Basis of Conductivity in Carbon Dioxide-Expanded Electrolytes: A Joint Experimental–Theoretical Study

Nilles,

Borkowski,

Bartlett

et al. 2024

J. Am. Chem. Soc.

View full text Add to dashboard Cite

show abstract

“…One of the most widely studied categories of ionic liquids in electrochemical CO 2 reduction is ionic liquids with imidazolium-derived cations. − Since the first report of using a 1,3-diakylimidazolium ionic liquid for CO 2 reduction to CO with unprecedently low overpotential, numerous studies have been performed to understand how imidazolium cations accelerate CO 2 reduction.…”

Section: Introductionmentioning

confidence: 99%

Suppressing Co-Ion Generation via Cationic Proton Donors to Amplify Driving Forces for Electrochemical CO₂ Reduction

2023

View full text Add to dashboard Cite

Interfacial microenvironments define reaction pathways for electrocatalytic processes through a combination of electric field gradients and proton activity. Nonaqueous ionic liquid electrolytes have been shown to sustain enhanced interfacial electric fields at intermediate ion concentration regimes of around 1 M, creating local environments that promote CO2 electroreduction. Notably, water at low concentrations absorbed by nonaqueous electrolytes is usually assumed to be the proton donor for CO2 reduction. Consumption of protons causes proton donors to become more negative by one unit of charge, which significantly modifies the local concentration of charged species and hence should strongly impact local electric fields. Yet, how the coupling between proton donation and changing interfacial electric fields influences electrocatalytic processes in nonaqueous electrolytes remains largely unexplored. In this work, we show that the high activity of 1,3-dialkylimidazolium ionic liquids for CO2 reduction in acetonitrile-based electrolytes stems from the ability to act as cationic proton donors that release neutral conjugate bases. Using in situ electrochemical surface-enhanced Raman spectroscopy, we find that the formation of neutral conjugate bases from imidazolium cations preserves local electric field strengths at electrode–electrolyte interfaces, providing a powerful strategy to maintain an active local microenvironment for CO2 reduction. In contrast, conditions where water behaves as the primary proton donor generate [OH]− anions as negative “co-ions” in the electric double layer, which weakens the interfacial electric field and significantly compromises the steady-state CO2 reduction activity. Our study highlights that electrochemical driving forces are highly sensitive to the charge state of both reactant and product species and illustrates that the generation of interfacial co-ions plays a key role in determining electrochemical driving forces.

show abstract

“…The presence of ionic liquids can greatly improve the solubility of CO 2 and ensure the effective supply of CO 2 in the ECR process, thus inhibiting the hydrogen evolution reaction (HER) and improving the catalytic activity and selectivity of ECR. [37][38][39][40][41] Therefore, we tested the ECR catalytic performance over the Cu/Zn-CP-1-30 electrode using electrolytes with different concentrations of [Bmim]PF 6 /MeCN at −2.5 V vs. Ag/ Ag + . It can be observed that the FE of CO changed with [Bmim] PF 6 content in the electrolytes (Fig.…”

Section: Resultsmentioning

confidence: 99%

Ultra-fast synthesis of three-dimensional porous Cu/Zn heterostructures for enhanced carbon dioxide electroreduction

Jia,

Zhu,

Han

et al. 2023

Chem. Sci.

Self Cite

View full text Add to dashboard Cite

show abstract

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

Cited by 28 publications

References 41 publications

Mechanistic Basis of Conductivity in Carbon Dioxide-Expanded Electrolytes: A Joint Experimental–Theoretical Study

Mechanistic Basis of Conductivity in Carbon Dioxide-Expanded Electrolytes: A Joint Experimental–Theoretical Study

Suppressing Co-Ion Generation via Cationic Proton Donors to Amplify Driving Forces for Electrochemical CO₂ Reduction

Ultra-fast synthesis of three-dimensional porous Cu/Zn heterostructures for enhanced carbon dioxide electroreduction

Contact Info

Product

Resources

About

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

Cited by 28 publications

References 41 publications

Mechanistic Basis of Conductivity in Carbon Dioxide-Expanded Electrolytes: A Joint Experimental–Theoretical Study

Mechanistic Basis of Conductivity in Carbon Dioxide-Expanded Electrolytes: A Joint Experimental–Theoretical Study

Suppressing Co-Ion Generation via Cationic Proton Donors to Amplify Driving Forces for Electrochemical CO2 Reduction

Ultra-fast synthesis of three-dimensional porous Cu/Zn heterostructures for enhanced carbon dioxide electroreduction

Contact Info

Product

Resources

About

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

Suppressing Co-Ion Generation via Cationic Proton Donors to Amplify Driving Forces for Electrochemical CO₂ Reduction