Electrocatalysis on Oxide-Stabilized, High-Surface Area Carbon Electrodes

Abstract

A procedure is described for preparing and derivatizing novel, high surface area electrodes consisting of thin layers of nanostructured ITO (Sn(IV)-doped indium tin oxide, nanoITO) on reticulated vitreous carbon (RVC) to give RVC|nanoITO. The resulting hybrid electrodes are highly stabilized oxidatively. They were surface-derivatized by phosphonate binding of the electrocatalyst, [Ru(Mebimpy)(4,4′-((HO)2OPCH2)2bpy)(OH2)]2+ (Mebimpy = 2,6-bis(1-methylbenzimidazol-2-yl)pyridine; bpy = 2,2′-bipyridine) (1-PO3H2) to give RVC|nanoITO-RuII-OH22+. The redox properties of the catalyst are retained on the electrode surface. Electrocatalytic oxidation of benzyl alcohol to benzaldehyde occurs with a 75% Faradaic efficiency compared to 57% on nanoITO. Electrocatalytic water oxidation at 1.4 V vs SCE on derivatized RVC|nanoITO electrode with an internal surface area of 19.5 cm2 produced 7.3 μmoles of O2 in 70% Faradaic yield in 50 min.