Graphite-Conjugated Rhenium Catalysts for Carbon Dioxide Reduction

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• 作者：Seokjoon Oh ; James R. Gallagher ; Jeffrey T. Miller ; Yogesh Surendranath
• 刊名：Journal of the American Chemical Society
• 出版年：2016
• 出版时间：February 17, 2016
• 年：2016
• 卷：138
• 期：6
• 页码：1820-1823
• 全文大小：294K
• ISSN：1520-5126

文摘

Condensation of fac-Re(5,6-diamino-1,10-phenanthroline)(CO)₃Cl to o-quinone edge defects on graphitic carbon surfaces generates graphite-conjugated rhenium (GCC-Re) catalysts that are highly active for CO₂ reduction to CO in acetonitrile electrolyte. X-ray photoelectron and X-ray absorption spectroscopies establish the formation of surface-bound Re centers with well-defined coordination environments. GCC-Re species on glassy carbon surfaces display catalytic currents greater than 50 mA cm⁻² with 96 ± 3% Faradaic efficiency for CO production. Normalized for the number of Re active sites, GCC-Re catalysts exhibit higher turnover frequencies than that of a soluble molecular analogue, fac-Re(1,10-phenanthroline)(CO)₃Cl, and turnover numbers greater than 12,000. In contrast to the molecular analogue, GCC-Re surfaces display a Tafel slope of 150 mV/decade, indicative of a catalytic mechanism involving rate-limiting one-electron transfer. This work establishes graphite-conjugation as a powerful strategy for generating well-defined, tunable, heterogeneous electrocatalysts on ubiquitous graphitic carbon surfaces.