Graphite Conjugation of a Macrocyclic Cobalt Complex Enhances Nitrite Electroreduction to Ammonia
Graphite Conjugation of a Macrocyclic Cobalt Complex Enhances Nitrite Electroreduction to Ammonia
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DOI：
10.1021/jacs.1c03427
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发表时间：
2021-05-03
影响因子：
15
通讯作者：
Smith, Jeremy M.
中科院分区：
文献类型：
--
作者：
Braley, Sarah E.;Xie, Jiaze;Smith, Jeremy M.
本工作报告的生成石墨共轭二亚胺大环钴催化剂（GCC-CoDIM），组装在石墨碳电极上的邻醌边缘缺陷。X-射线光电子能谱和X-射线吸收光谱证实了一种新的Co表面物种的存在，其配位环境与分子类似物[Co（DIM）Br-2]（+）的配位环境相同。GCC-CoDIM以定量法拉第效率和接近酶催化的速率选择性地将亚硝酸盐还原为铵。初步的机制研究表明，增加的速率是伴随着从分子类似物的机制的变化。这些结果提供了一个模板，用于创建基于大环的电催化剂的第一行过渡金属共轭极端氧化还原活性配体的基础上。
This work reports on the generation of a graphite-conjugated diimine macrocyclic Co catalyst (GCC-CoDIM) that is assembled at o-quinone edge defects on graphitic carbon electrodes. X-ray photoelectron spectroscopy and X-ray absorption spectroscopy confirm the existence of a new Co surface species with a coordination environment that is the same as that of the molecular analogue, [Co(DIM)Br-2](+). GCC-CoDIM selectively reduces nitrite to ammonium with quantitative Faradaic efficiency and at a rate that approaches enzymatic catalysis. Preliminary mechanistic investigations suggest that the increased rate is accompanied by a change in mechanism from the molecular analogue. These results provide a template for creating macrocycle-based electrocatalysts based on first-row transition metals conjugated to an extreme redox-active ligand.