title: Selective electrocatalytic oxidation of a re-methyl complex to methanol by a surface-bound Ru(II) polypyridyl catalyst.
abstract: The complex [Ru(Mebimpy)(4,4'-((HO)2OPCH2)2bpy)(OH2)](2+) surface bound to tin-doped indium oxide mesoporous nanoparticle film electrodes (nanoITO-Ru(II)(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-Ru(IV)(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(-1). 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-Ru(V)(O)(3+) leads to multiple electrolysis products. The results of an electrochemical kinetics study point to a mechanism in which surface oxidation to nanoITO-Ru(IV)(OH)(3+) is followed by direct insertion into the rhenium-methyl bond of MTO with a detectable intermediate.
authors.affiliation: Department of Chemistry, University of North Carolina at Chapel Hill , Chapel Hill, North Carolina 27599, United States.
authors.forename: Michael K
authors.initials: MK
authors.lastname: Coggins
authors.forename: Manuel A
authors.initials: MA
authors.lastname: Méndez
authors.forename: Javier J
authors.initials: JJ
authors.lastname: Concepcion
authors.forename: Roy A
authors.initials: RA
authors.lastname: Periana
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Meyer