Ke Ye , Guiru Zhang , Baoxin Ni , Liang Guo , Chengwei Deng , Xiaodong Zhuang , Changying Zhao , Wen-Bin Cai , Kun Jiang
{"title":"Steering CO2 electrolysis selectivity by modulating the local reaction environment: An online DEMS approach for Cu electrodes","authors":"Ke Ye , Guiru Zhang , Baoxin Ni , Liang Guo , Chengwei Deng , Xiaodong Zhuang , Changying Zhao , Wen-Bin Cai , Kun Jiang","doi":"10.1016/j.esci.2023.100143","DOIUrl":null,"url":null,"abstract":"<div><p>Electrochemical CO<sub>2</sub> reduction is a typical surface-mediated reaction, with its reaction kinetics and product distributions largely dependent on the dynamic evolution of reactive species at the cathode–catholyte interface and on the resultant mass transport within the hydrodynamic boundary layer in the vicinity of the cathode. To resolve the complex local reaction environment of branching CO<sub>2</sub> reduction pathways, we here present a differential electrochemical mass spectroscopic (DEMS) approach for Cu electrodes to investigate CO<sub>2</sub> mass transport, the local concentration gradients of buffering anions, and the Cu surface topology effects on CO<sub>2</sub> electrolysis selectivity at a temporal resolution of ∼400 ms. As a proof of concept, these tuning knobs were validated on an anion exchange membrane electrolyzer, which delivered a Faradaic efficiency of up to 40.4% and a partial current density of 121 mA cm<sup>−2</sup> for CO<sub>2</sub>-to-C<sub>2</sub>H<sub>4</sub> valorization. This methodology, which bridges the study of fundamental surface electrochemistry and the upgrading of practical electrolyzer performance, could be of general interest in helping to achieve a sustainable circular carbon economy.</p></div>","PeriodicalId":100489,"journal":{"name":"eScience","volume":"3 4","pages":"Article 100143"},"PeriodicalIF":42.9000,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"4","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"eScience","FirstCategoryId":"1085","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S266714172300068X","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ELECTROCHEMISTRY","Score":null,"Total":0}
引用次数: 4
Abstract
Electrochemical CO2 reduction is a typical surface-mediated reaction, with its reaction kinetics and product distributions largely dependent on the dynamic evolution of reactive species at the cathode–catholyte interface and on the resultant mass transport within the hydrodynamic boundary layer in the vicinity of the cathode. To resolve the complex local reaction environment of branching CO2 reduction pathways, we here present a differential electrochemical mass spectroscopic (DEMS) approach for Cu electrodes to investigate CO2 mass transport, the local concentration gradients of buffering anions, and the Cu surface topology effects on CO2 electrolysis selectivity at a temporal resolution of ∼400 ms. As a proof of concept, these tuning knobs were validated on an anion exchange membrane electrolyzer, which delivered a Faradaic efficiency of up to 40.4% and a partial current density of 121 mA cm−2 for CO2-to-C2H4 valorization. This methodology, which bridges the study of fundamental surface electrochemistry and the upgrading of practical electrolyzer performance, could be of general interest in helping to achieve a sustainable circular carbon economy.
电化学CO2还原是一种典型的表面介导反应,其反应动力学和产物分布在很大程度上取决于阴极-阴极界面反应物质的动态演化以及阴极附近流体动力边界层内由此产生的质量传递。为了解决分支CO2还原途径的复杂局部反应环境,我们在此提出了一种差分电化学质谱(dem)方法,用于Cu电极研究CO2的质量传输,缓冲阴离子的局部浓度梯度以及Cu表面拓扑结构对CO2电解选择性的影响,时间分辨率为~ 400 ms。作为概念验证,这些调谐旋钮在阴离子交换膜电解槽上进行了验证,其法拉第效率高达40.4%,分电流密度为121 mA cm−2,用于二氧化碳到c2h4的增值。这种方法将基础表面电化学的研究与实际电解槽性能的升级联系起来,可能有助于实现可持续的循环碳经济。