title: Electrochemical generation of free nitric oxide from nitrite catalyzed by iron meso-tetrakis(4-N-methylpyridiniumyl)porphyrin.
abstract: Electrochemical generation of free nitric oxide (NO) from nitrite (NO(2)(-)) catalyzed by iron meso-tetrakis(4-N-methylpyridiniumyl)porphyrin, [Fe(III)(TMPyP)](5+), has been developed in this study. To obtain free NO, a cathodic electrolysis and an anodic electrolysis were performed in two connected flow electrolytic cells in sequence. The flow electrolytic cell upstream was used for cathodic electrolysis, where the solution of [Fe(III)(TMPyP)](5+) and NO(2)(-) was reduced at -0.25 V (vs Ag/AgCl) into [Fe(II)(NO(2)(-))(2)(TMPyP)](2+) and [Fe(II)(NO)(TMPyP)](4+) in sequence. The flow electrolytic cell downstream was utilized for anodic electrolysis, where [Fe(II)(NO)(TMPyP)](4+) formed from the upstream cell was oxidized at +0.40 V (vs Ag/AgCl) into [Fe(III)(TMPyP)](5+) and free NO. Finally, NO was bubbled out from anodic electrolyte by argon gas. The mechanism and the optimum conditions for electrochemical generation of NO from NO(2)(-) catalyzed by [Fe(III)(TMPyP)](5+) were studied in detail by voltammetric and spectroelectrochemical methods.
authors.affiliation: Department of Applied Physics, Faculty of Engineering, University of Fukui, 3-9-1 Bunkyo, Fukui-shi 910-8507, Japan. y.w.chi@asura.apphy.fukui-u.ac.jp
authors.forename: Yuwu
authors.initials: Y
authors.lastname: Chi
authors.forename: Jingyuan
authors.initials: J
authors.lastname: Chen
authors.forename: Koichi
authors.initials: K
authors.lastname: Aoki
mesh_terms: D000465:Algorithms; D002384:Catalysis; D004563:Electrochemistry / Q000295:instrumentation; D007501:Iron / Q000737:chemistry*; D008665:Metalloporphyrins / Q000737:chemistry*; D009569:Nitric Oxide / Q000138:chemical synthesis*; D009573:Nitrites / Q000737:chemistry*; D010084:Oxidation-Reduction; D011726:Pyridinium Compounds / Q000737:chemistry*
chemical_list: D008665:Metalloporphyrins; D009573:Nitrites; D011726:Pyridinium Compounds; D009569:Nitric Oxide; D007501:Iron