Kim Moonjoo, Park Sangmee, Chung Taek Dong
Department of Chemistry, Seoul National University Seoul 08826 Republic of Korea
Program in Nano Science and Technology, Graduate School of Convergence Science and Technology, Seoul National University Suwon-si Gyeonggi-do 16229 Republic of Korea.
Chem Sci. 2022 Jul 13;13(30):8821-8828. doi: 10.1039/d2sc01410f. eCollection 2022 Aug 4.
In ionic liquids (ILs), the electric double layer (EDL) is where heterogeneous electron transfer (ET) occurs. Nevertheless, the relationship between the EDL structure and its kinetics has been rarely studied, especially for ET taking place in the inner Helmholtz plane (IHP). This is largely because of the lack of an appropriate model system for experiments. In this work, we determined the reorganization energy () of Br reduction in a redox-active IL 1-ethyl-1-methylpyrrolidinium polybromide (MEPBr) based on the Marcus-Hush-Chidsey model. Exceptionally fast mass transport of Br in MEPBr allows voltammograms to be obtained in which the current plateau is regulated by electron-transfer kinetics. This enables investigation of the microscopic environment in the IHP of the IL affecting electrocatalytic reactions through reorganization energy. As a demonstration, TiO-modified Pt was employed to show pH-dependent reorganization energy, which suggests the switch of major ions at the IHP as a function of surface charges of electrodes.
在离子液体（ILs）中，电双层（EDL）是异相电子转移（ET）发生的场所。然而，EDL结构与其动力学之间的关系很少被研究，特别是对于发生在内亥姆霍兹平面（IHP）的电子转移。这主要是因为缺乏适用于实验的模型系统。在这项工作中，我们基于Marcus-Hush-Chidsey模型确定了氧化还原活性离子液体1-乙基-1-甲基吡咯烷鎓多溴化物（MEPBr）中Br还原的重组能（）。MEPBr中Br异常快速的质量传输使得能够获得伏安图，其中电流平台由电子转移动力学调节。这使得能够通过重组能研究离子液体IHP中影响电催化反应的微观环境。作为示例，使用TiO修饰的Pt来显示pH依赖性重组能，这表明IHP处主要离子随电极表面电荷的变化。
