Armand Bettelheim

Electroanalysis of oxygen reduction: Part III. Selective reduction to hydrogen peroxide or water using polymeric attachment of metalloporphyrins

Abstract Fe(III) tetra-( o -aminophenyl)porphyrin and Fe(III) tetra-( N -(2-hydroxyethyl)pyridyl)-porphyrin were attached to glassy carbon electrodes through amidization or esterifification of the methyl acryl chloride polymer. Long-term stability as well as high coverage (up to 10 −9 mol cm −2 ) enabled these electrodes to be useful with respect to catalysis of oxygen reduction. The reduction of O 2 to H 2 O 2 or H 2 O can be controlled by changing the surface coverage of the porphyrin. Based on results obtained for dissolved, adsorbed and polymercoated porphyrin, a general mechanism, for O 2 electrocatalysis is proposed.

Ligation and Mediated Oxidation of Nitrogen Monoxide by Nickel(II) Tetrasulfonated Phthalocyanine

Ligation and mediated electro-oxidation of NO by the water soluble Ni(II) tetrasulfonated phthalocyanine (Ni(II)TSPc) at pH 7 to 9 is demonstrated using spectroscopic (ultraviolet-visible, Fourier transform infrared, and electron spin resonance) and electrochemical (cyclic voltammetry) techniques. The experimental results are in favor of the formation of a Ni(III)TSPc (NO - ) complex in solution.

Spectroscopic and electrochemical response to nitrogen monoxide of a cationic iron porphyrin immobilized in nafion-coated electrodes or membranes

Nafion membranes containing immobilized FeIII tetrakis(N-methyl-4-pyridyl)porphyrin show spectroscopic changes in the UV–VIS range after exposure to gaseous NO, indicating the formation of a nitrosyl complex; electroreduction of NO is mediated by this metalloporphyrin when immobilized in Nafion-coated glassy-carbon electrodes and the use of these film electrodes for the amperometric determination of NO in aqueous solutions is demonstrated.