Electrocatalysis on Oxide-Stabilized, High-Surface\nArea Carbon Electrodes

Abstract

A procedure is described for preparing\nand derivatizing novel,\nhigh surface area electrodes consisting of thin layers of nanostructured\nITO (Sn­(IV)-doped indium tin oxide, <i>nano</i>ITO) on reticulated\nvitreous carbon (RVC) to give RVC|<i>nano</i>ITO. The resulting\nhybrid electrodes are highly stabilized oxidatively. They were surface-derivatized\nby 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)\n(<b>1-PO</b>_<b>3</b><b>H</b>_<b>2</b>) to give RVC|<i>nano</i>ITO-Ru^II-OH₂²⁺. The redox properties of the catalyst\nare retained on the electrode surface. Electrocatalytic oxidation\nof benzyl alcohol to benzaldehyde occurs with a 75% Faradaic efficiency\ncompared to 57% on <i>nano</i>ITO. Electrocatalytic water\noxidation at 1.4 V vs SCE on derivatized RVC|<i>nano</i>ITO electrode with an internal surface area of 19.5 cm² produced 7.3 μmoles of O₂ in 70% Faradaic yield\nin 50 min.