Selective Electrocatalytic Oxidation of a Re鈥揗ethyl Complex to Methanol by a Surface-Bound RuII Polypyridyl Catalyst
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- 作者：Michael K. Coggins ; Manuel A. M茅ndez ; Javier J. Concepcion ; Roy A. Periana ; Thomas J. Meyer
- 刊名：Journal of the American Chemical Society
- 出版年：2014
- 出版时间：November 12, 2014
- 年：2014
- 卷：136
- 期：45
- 页码：15845-15848
- 全文大小：275K
- ISSN：1520-5126
文摘
The complex [Ru(Mebimpy)(4,4鈥?((HO)2OPCH2)2bpy)(OH2)]2+ surface bound to tin-doped indium oxide mesoporous nanoparticle film electrodes (nanoITO-RuII(OH2)2+) is an electrocatalyst for the selective oxidation of methylrhenium trioxide (MTO) to methanol in acidic aqueous solution. Oxidative activation of the catalyst to nanoITO-RuIV(OH)3+ induces oxidation of MTO. The reaction is first order in MTO with rate saturation observed at [MTO] > 12 mM with a limiting rate constant of k = 25 s鈥?. Methanol is formed selectively in 87% Faradaic yield in controlled potential electrolyses at 1.3 V vs NHE. At higher potentials, oxidation of MTO by nanoITO-RuV(O)3+ leads to multiple electrolysis products. The results of an electrochemical kinetics study point to a mechanism in which surface oxidation to nanoITO-RuIV(OH)3+ is followed by direct insertion into the rhenium鈥搈ethyl bond of MTO with a detectable intermediate.