title: Photochemical production of hydrogen from water using microporous porphyrin coordination lattices.
abstract: In this study, we investigated the photochemical production of hydrogen from water using bio-inspired heterogeneous microporous porphyrin coordination lattices (PCLs), [Ru2(MTCPP)BF4] (M = H2 (PCL-1), Zn (PCL-2); TCPP = Tetrakis(4-carboxyphenyl)porphyrin), under visible (380 nm <) and UV (320 nm <) light irradiations. In the presence of Na2EDTA (as a sacrificial donor) and MV2+ (methyl-vilologen; as a electron relay), PCLs exhibits photocatalytic activity for hydrogen evolution; the maximum amounts of turnover numbers (TONs) of PCL-1 and PCL-2 at 24 h irradiation were 20.8 and 29.9, respectively. In the catalytic reactions, the relation between PCLs and MV2+ was similar to the relation between a [cytochrome c3 hydrogenase] pair and lysine residues in enzymatic reactions. By using the hydrogen production rate and the MV+ (methyl-vilologen radical-cation) concentration, kinetic parameters such as affinities between MV+ and PCLs, maximum reaction rate, and total efficiency of the reaction are introduced using the Michaelis-Menten equation. These parameters indicated that PCLs are good artificial enzyme model catalysts. The stability of the PCLs after the catalytic reactions was confirmed by X-ray photoelectron spectroscopy and Fourier transform-infrared spectra. These results indicated that the frameworks of PCLs are stable for this catalytic reaction.
authors.affiliation: Department of Chemistry, Faculty of Science, Kanagawa University, 2946, Tsuchiya, Hiratsuka, Kanagawa 259-1293, Japan.
authors.forename: Konomi
authors.initials: K
authors.lastname: Sato
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Kataoka
authors.forename: Wasuke
authors.initials: W
authors.lastname: Mori
mesh_terms: D006859:Hydrogen / Q000737:chemistry* / Q000302:isolation & purification* / Q000528:radiation effects; D008422:Materials Testing; D049329:Nanostructures / Q000737:chemistry* / Q000528:radiation effects*; D010777:Photochemistry / Q000379:methods; D016062:Porosity; D011166:Porphyrins / Q000737:chemistry*; D014867:Water / Q000737:chemistry*
chemical_list: D011166:Porphyrins; D014867:Water; D006859:Hydrogen