Strong Electronic Coupling of Molecular Sites to Graphitic Electrodes via Pyrazine Conjugation
Strong Electronic Coupling of Molecular Sites to Graphitic Electrodes via Pyrazine Conjugation
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DOI：
10.1021/jacs.7b10723
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发表时间：
2018-01-24
影响因子：
15
通讯作者：
Surendranath, Yogesh
中科院分区：
文献类型：
--
作者：
Jackson, Megan N.;Oh, Seokjoon;Surendranath, Yogesh
玻碳电极功能化与氧化还原活性部分通过缩合邻苯二胺：衍生物与邻醌网站原生石墨碳表面。电化学和光谱研究表明，这些石墨共轭催化剂（GCcs）表现出很强的电子耦合到电极，导致电子转移（ET）的行为，从根本上偏离的溶液相。或-表面栓系的类似物。我们发现（1）无论施加的电位如何，在电极和氧化还原活性GCC部分之间都没有观察到ET。(2)只有当界面反应是离子耦合时，才能在GCC处观察到ET。(3)即使是在。观察到ET时，过渡金属GCC位点的氧化态保持不变。从这些观察，我们构建了一个GCC网站的机制模型，其中ET行为是相同的催化活性的金属表面，而不是在溶液中的分子。这些结果表明，GCC提供了一个通用的平台，桥接分子和多相电催化。
Glassy carbon electrodes were functionalized with redox-active moieties by condensation of o-phenylenediamine :derivatives with o-quinone sites native to graphitic carbon surfaces. Electrochemical and spectroscopic investigations establish that these graphite-conjugated catalysts (GCcs) exhibit strong electronic coupling to the electrode, leading to electron transfer (ET) behavior that diverges fundamentally from that of solution-phase. or-Surface-tethered analogues. We find that (1) ET is not observed between the electrode and a redox-active GCC moiety regardless of applied potential. (2) ET is observed at GCCs only if the interfacial reaction is ion coupled. (3) Even when. ET is observed, the oxidation state of a transition metal GCC site remains unchanged. From these observations, we construct a mechanistic model for GCC sites in which ET behavior is identical to that of catalytically active metal surfaces rather than to that of molecules in solution. These results suggest that GCCs provide a versatile platform for bridging molecular and heterogeneous electrocatalysis.