Direct Detection of Electron Transfer Reactions Underpinning the Tin-Catalyzed Electrochemical Reduction of CO2 using Fourier-Transformed ac Voltammetry
Direct Detection of Electron Transfer Reactions Underpinning the Tin-Catalyzed Electrochemical Reduction of CO2 using Fourier-Transformed ac Voltammetry
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DOI：
10.1021/acscatal.7b01305
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发表时间：
2017-06
期刊：
影响因子：
12.9
通讯作者：
Ying Zhang;Lu Chen;Fengwang Li;C. Easton;Jiezhen Li;A. Bond;Jie Zhang
中科院分区：
文献类型：
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作者：
Ying Zhang;Lu Chen;Fengwang Li;C. Easton;Jiezhen Li;A. Bond;Jie Zhang
两个基本的电子转移过程，直接支撑的催化还原二氧化碳（CO2）的HCOO-和CO在锡电极已被检测到使用高次谐波成分可在傅立叶变换大振幅交流伏安法。这两个紧密间隔的电子转移过程都不能通过直流伏安法检测到，并且与CO2物质的直接还原有关，并且具有相对于Ag/AgCl（1 M KCl）约为−1.27和−1.40 V的可逆电位。提出了一种包括CO2的可逆内球单电子还原和CO2·-质子化步骤的反应机理。CO2分子是主要的电活性物种，它通过一系列耦合的电子转移和化学反应形成最终产物。Sn（SnOx）修饰的玻碳电极和Sn箔电极的催化响应的显著差异归因于它们强烈的择优Sn（200）取向和多晶性。
Two underlying electron transfer processes that directly underpin the catalytic reduction of carbon dioxide (CO2) to HCOO– and CO at Sn electrodes have been detected using the higher order harmonic components available in Fourier-transformed large-amplitude ac voltammetry. Both closely spaced electron transfer processes are undetectable by dc voltammetry and are associated with the direct reduction of CO2 species and have reversible potentials of approximately −1.27 and −1.40 V vs Ag/AgCl (1 M KCl). A mechanism involving a reversible inner-sphere one-electron reduction of CO2 followed by a rate-determining CO2•– protonation step is proposed. Molecular CO2 has been identified as the dominant electroactive species that undergoes a series of coupling electron transfer and chemical reactions to form the final products. The substantial difference in the catalytic responses of Sn(SnOx)-modified glassy carbon and Sn foil electrodes are attributed to their strongly preferred Sn (200) orientation and polycrystalli...