Single-Site, Catalytic Water Oxidation on Oxide Surfaces

Abstract

Electrocatalytic water oxidation occurs through the use of the phosphonate-derivatized single-site catalyst [Ru(Mebimpy)(4,4'-((HO)(2)OPCH(2))(2)bpy)(OH(2))](2+) [Mebimpy = 2,6-bis(1-methylbenzimidazol-2-yl)pyridine; bpy = 2,2'-bipyridine] at pH 1 and 5 on fluorine-doped SnO(2) or Sn(IV)-doped In(2)O(3) electrodes or on nanocrystalline TiO(2). The surface-bound catalyst appears to retain the water oxidation mechanism found for [Ru(tpy)(bpm)(OH(2))](2+) and [Ru(tpy)(bpz)(OH(2))](2+) (tpy = 2,2':6',2''-terpyridine; bpm = 2,2'-bipyrimidine; bpz = 2,2'-bipyrazine) in solution and acts as a surface electrocatalyst for sustained water oxidation.