title: Cobalt porphyrins as homogeneous catalysts for water oxidation.
abstract: Three water-soluble cobalt porphyrins have been investigated as water oxidation catalysts via photo-initiation using Ru(II)(bpy)3(2+)/Na2S2O8. The pH dependence of the turnover frequency revealed maximum activity at pH 11. Based on the second order dependence on catalyst concentration for the rate of water oxidation, we suggest a bimolecular radical coupling process as the rate determining step.
authors.affiliation: Department of Chemistry, Faculty of Sciences, Kyushu University, 6-10-1 Hakozaki, Fukuoka 812-8581, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Nakazono
authors.forename: Alexander Rene
authors.initials: AR
authors.lastname: Parent
authors.forename: Ken
authors.initials: K
authors.lastname: Sakai
mesh_terms: D002384:Catalysis; D003035:Cobalt / Q000737:chemistry*; D008665:Metalloporphyrins / Q000737:chemistry*; D015394:Molecular Structure; D010084:Oxidation-Reduction; D014867:Water / Q000737:chemistry*
chemical_list: D008665:Metalloporphyrins; D014867:Water; D003035:Cobalt