Ionic Liquid Enhanced Proton Transfer for Neutral Oxygen Evolution Reaction

Authors

Mingxing Chen, Henan Engineering Research Center of Design and Recycle for Advanced Electrochemical Energy Storage Materials, School of Materials Science and Engineering Henan Normal University, Xinxiang 453007, China.
Nian Liu, Henan Engineering Research Center of Design and Recycle for Advanced Electrochemical Energy Storage Materials, School of Materials Science and Engineering Henan Normal University, Xinxiang 453007, China.
Zihe Du, Henan Engineering Research Center of Design and Recycle for Advanced Electrochemical Energy Storage Materials, School of Materials Science and Engineering Henan Normal University, Xinxiang 453007, China.
Jing Qi, Henan Engineering Research Center of Design and Recycle for Advanced Electrochemical Energy Storage Materials, School of Materials Science and Engineering Henan Normal University, Xinxiang 453007, China.
Rui Cao, Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi’an 710119, China.

Document Type

Article

Corresponding Author(s)

Jing Qi(qijing2020@htu.edu.cn);
Rui Cao(ruicao@snnu.edu.cn)

Abstract

The development of highly active catalyst in pH-neutral media for oxygen evolution reaction (OER) is critical in the field of renewable energy storage and conversion. Nevertheless, the slow kinetics of proton-coupled electron transfer (PCET) hinders the overall OER efficiency. Herein, we report an ionic liquid (IL) modified CoSn(OH)₆ nanocubes (denoted as CoSn(OH)₆-IL), which could be prepared through a facile strategy. The modified IL would not change the structural characteristics of CoSn(OH)₆, but could effectively regulate the local proton activity near the active sites. CoSn(OH)₆-IL exhibits higher intrinsic OER performances than the pristine CoSn(OH)₆ in neutral media. For example, the current density of CoSn(OH)₆-IL at 1.8 V versus reversible hydrogen electrode (RHE) is about 4 times higher than that of CoSn(OH)₆. According to the pH-dependent kinetic investigations, operando electrochemical impedance spectroscopy, chemical probe tests and deuterium kinetic isotope effects, the interfacial layer of IL can be utilized as a proton transfer mediator to promote the proton transfer, which enhances the surface coverage of OER intermediates and reduces the activation barrier. Consequently, the sluggish OER kinetics is efficiently accelerated. This study provides a facile an effective strategy to facilitate the PCET processes and is beneficial to guide the rational design of OER electrocatalysts.

Graphical Abstract

Keywords

electrocatalysis, oxygen evolution reaction, ionic liquid, proton transfer, CoSn(OH)6 nanocube

DOI

10.61558/2993-074X.3549

Online Date

5-16-2025

Recommended Citation

Mingxing Chen, Nian Liu, Zihe Du, Jing Qi, Rui Cao. Ionic Liquid Enhanced Proton Transfer for Neutral Oxygen Evolution Reaction[J]. Journal of Electrochemistry, doi: 10.61558/2993-074X.3549.