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Ch. Comninellis - One of the best experts on this subject based on the ideXlab platform.
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electrogeneration of hydroxyl radicals on boron doped diamond electrodes
Journal of The Electrochemical Society, 2003Co-Authors: Beatrice Marselli, P A Michaud, J Garciagomez, Manuel A Rodrigo, Ch. ComninellisAbstract:The electrogeneration of hydroxyl radicals was studied at a synthetic B-doped diamond (BDD) thin film electrode. Spin trapping was used for detection of hydroxyl radicals with 5,5-dimethyl-1-pyrroline-N-oxide and with salicylic acid using ESR and liq. chromatog. measurements, resp. The prodn. of H2O2 and competitive oxidn. of formic and oxalic acids were also studied using Bulk Electrolysis. Oxidn. of salicylic acid gives hydroxylated products (2,3- and 2,5-dihydroxybenzoic acids). The oxidn. process on BDD electrodes involves hydroxyl radicals as electrogenerated intermediates. [on SciFinder (R)]
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electrogeneration of hydroxyl radicals on boron doped diamond electrodes
Journal of The Electrochemical Society, 2003Co-Authors: Beatrice Marselli, P A Michaud, J Garciagomez, Manuel A Rodrigo, Ch. ComninellisAbstract:The electrogeneration of hydroxyl radicals was studied at a synthetic B-doped diamond (BDD) thin film electrode. Spin trapping was used for detection of hydroxyl radicals with 5,5-dimethyl-1-pyrroline-N-oxide and with salicylic acid using ESR and liq. chromatog. measurements, resp. The prodn. of H2O2 and competitive oxidn. of formic and oxalic acids were also studied using Bulk Electrolysis. Oxidn. of salicylic acid gives hydroxylated products (2,3- and 2,5-dihydroxybenzoic acids). The oxidn. process on BDD electrodes involves hydroxyl radicals as electrogenerated intermediates. [on SciFinder (R)]
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electrochemical oxidation of benzoic acid at boron doped diamond electrodes
Electrochimica Acta, 2002Co-Authors: F Montilla, P A Michaud, Emilia Morallon, J L Vazquez, Ch. ComninellisAbstract:The electrochemical oxidation of benzoic acid (BA) has been studied on boron-doped diamond electrodes on acid medium by cyclic voltammetry and Bulk Electrolysis. The results showed that in the potential region where the supporting electrolyte is stable, reactions occur, resulting in the loss of activity due to electrode fouling. Electrolysis at high anodic potentials in the region of electrolyte decomposition causes complex oxidation reactions that lead to incineration of BA. There is no indication of electrode fouling. Salicylic acid, 2,5-hydroxybenzoic acid and hydroquinone have been detected at trace level by HPLC as soluble products during the Electrolysis of BA.
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electro combustion of polyacrylates with boron doped diamond anodes
Electrochemistry Communications, 2002Co-Authors: R Bellagamba, P A Michaud, Ch. Comninellis, Nicolaos VatistasAbstract:The electro-combustion of water sol. polymeric contaminants such as polyacrylates (PA) in aq. acid soln. using a B-doped diamond anode was studied by Bulk Electrolysis in 1 mol/dm3 HClO4 under galvanostatic conditions in a wide range of PA concns. and current densities. In all cases complete electro-combustion of PA was achieved and this is the 1st successful report for the electro-combustion of sol. org. polymers. The exptl. COD and instantaneous current efficiency values are well predicted from a theor. model which suppose that the rate of electro-combustion of PA with electrogenerated active intermediates (probably hydroxyl radicals) is a fast reaction and is controlled by mass transport of PA towards the anode (concept of the ideal anode for electro-combustion). [on SciFinder (R)]
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electrochemical oxidation of phenol at boron doped diamond electrode
Electrochimica Acta, 2001Co-Authors: J Iniesta, P A Michaud, Marco Panizza, G Cerisola, A Aldaz, Ch. ComninellisAbstract:The electrochemical oxidation of phenol at synthetic boron-doped diamond thin film electrode (BDD) has been studied in acid media by cyclic voltammetry, chronoamperometry and Bulk Electrolysis. The results have shown that in the potential region of water stability (E 2.3 V vs. SHE), indirect oxidation reactions can take place by electrogenerated active intermediates, probably hydroxyl radicals, which can avoid electrode fouling. Depending on the values of applied current, and phenol concentration it is possible to obtain the complete combustion of phenol to CO2 or the partial oxidation of phenol to other aromatic compounds (benzoquinone, hydroquinone, catechol).
P A Michaud - One of the best experts on this subject based on the ideXlab platform.
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electrogeneration of hydroxyl radicals on boron doped diamond electrodes
Journal of The Electrochemical Society, 2003Co-Authors: Beatrice Marselli, P A Michaud, J Garciagomez, Manuel A Rodrigo, Ch. ComninellisAbstract:The electrogeneration of hydroxyl radicals was studied at a synthetic B-doped diamond (BDD) thin film electrode. Spin trapping was used for detection of hydroxyl radicals with 5,5-dimethyl-1-pyrroline-N-oxide and with salicylic acid using ESR and liq. chromatog. measurements, resp. The prodn. of H2O2 and competitive oxidn. of formic and oxalic acids were also studied using Bulk Electrolysis. Oxidn. of salicylic acid gives hydroxylated products (2,3- and 2,5-dihydroxybenzoic acids). The oxidn. process on BDD electrodes involves hydroxyl radicals as electrogenerated intermediates. [on SciFinder (R)]
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electrogeneration of hydroxyl radicals on boron doped diamond electrodes
Journal of The Electrochemical Society, 2003Co-Authors: Beatrice Marselli, P A Michaud, J Garciagomez, Manuel A Rodrigo, Ch. ComninellisAbstract:The electrogeneration of hydroxyl radicals was studied at a synthetic B-doped diamond (BDD) thin film electrode. Spin trapping was used for detection of hydroxyl radicals with 5,5-dimethyl-1-pyrroline-N-oxide and with salicylic acid using ESR and liq. chromatog. measurements, resp. The prodn. of H2O2 and competitive oxidn. of formic and oxalic acids were also studied using Bulk Electrolysis. Oxidn. of salicylic acid gives hydroxylated products (2,3- and 2,5-dihydroxybenzoic acids). The oxidn. process on BDD electrodes involves hydroxyl radicals as electrogenerated intermediates. [on SciFinder (R)]
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electrochemical oxidation of benzoic acid at boron doped diamond electrodes
Electrochimica Acta, 2002Co-Authors: F Montilla, P A Michaud, Emilia Morallon, J L Vazquez, Ch. ComninellisAbstract:The electrochemical oxidation of benzoic acid (BA) has been studied on boron-doped diamond electrodes on acid medium by cyclic voltammetry and Bulk Electrolysis. The results showed that in the potential region where the supporting electrolyte is stable, reactions occur, resulting in the loss of activity due to electrode fouling. Electrolysis at high anodic potentials in the region of electrolyte decomposition causes complex oxidation reactions that lead to incineration of BA. There is no indication of electrode fouling. Salicylic acid, 2,5-hydroxybenzoic acid and hydroquinone have been detected at trace level by HPLC as soluble products during the Electrolysis of BA.
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electro combustion of polyacrylates with boron doped diamond anodes
Electrochemistry Communications, 2002Co-Authors: R Bellagamba, P A Michaud, Ch. Comninellis, Nicolaos VatistasAbstract:The electro-combustion of water sol. polymeric contaminants such as polyacrylates (PA) in aq. acid soln. using a B-doped diamond anode was studied by Bulk Electrolysis in 1 mol/dm3 HClO4 under galvanostatic conditions in a wide range of PA concns. and current densities. In all cases complete electro-combustion of PA was achieved and this is the 1st successful report for the electro-combustion of sol. org. polymers. The exptl. COD and instantaneous current efficiency values are well predicted from a theor. model which suppose that the rate of electro-combustion of PA with electrogenerated active intermediates (probably hydroxyl radicals) is a fast reaction and is controlled by mass transport of PA towards the anode (concept of the ideal anode for electro-combustion). [on SciFinder (R)]
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electrochemical oxidation of phenol at boron doped diamond electrode
Electrochimica Acta, 2001Co-Authors: J Iniesta, P A Michaud, Marco Panizza, G Cerisola, A Aldaz, Ch. ComninellisAbstract:The electrochemical oxidation of phenol at synthetic boron-doped diamond thin film electrode (BDD) has been studied in acid media by cyclic voltammetry, chronoamperometry and Bulk Electrolysis. The results have shown that in the potential region of water stability (E 2.3 V vs. SHE), indirect oxidation reactions can take place by electrogenerated active intermediates, probably hydroxyl radicals, which can avoid electrode fouling. Depending on the values of applied current, and phenol concentration it is possible to obtain the complete combustion of phenol to CO2 or the partial oxidation of phenol to other aromatic compounds (benzoquinone, hydroquinone, catechol).
G Cerisola - One of the best experts on this subject based on the ideXlab platform.
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Anodic oxidation of mecoprop herbicide at lead dioxide
Journal of Applied Electrochemistry, 2008Co-Authors: Marco Panizza, Ignasi Sirés, G CerisolaAbstract:The electrochemical oxidation of an aqueous solution containing mecoprop (2-(2-methyl-4-chlorophenoxy)propionic acid) has been studied at PbO_2 anodes by cyclic voltammetry and Bulk Electrolysis. The influence of current density, hydrodynamic conditions, temperature and pH on the degradation rate and current efficiency is reported. The results obtained show that the use of PbO_2 leads to total mineralization of mecoprop due to the production of oxidant hydroxyl radical electrogenerated from water discharge. The current efficiency for the electro-oxidation of mecoprop is enhanced by low current density, high recycle flow-rates and high temperature. In contrast, the pH effect was not significant. It has also been observed that mecoprop decay kinetics follows a pseudo-first-order reaction and the rate constant increases with rising current density.
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electrocatalytic materials for the electrochemical oxidation of synthetic dyes
Applied Catalysis B-environmental, 2007Co-Authors: Marco Panizza, G CerisolaAbstract:Abstract The electrocatalytic properties of Ti–Ru–Sn ternary oxide, platinum, lead dioxide and boron-doped diamond anodes for the oxidation of methyl red have been compared by potentiodynamic measurements and Bulk Electrolysis. The results of the cyclic voltammetries have shown that in the potential region of supporting electrolyte stability polymeric materials, which result in electrode deactivation, are formed on the electrode surfaces. While Ti–Ru–Sn ternary oxide and platinum cannot restore their initial activity by polarization, lead dioxide and boron-doped diamond anodes can be reactivated by Electrolysis in the potential region of electrolyte decomposition due to the electrogeneration of hydroxyl radicals. The Bulk Electrolysis showed that the complete COD and colour removal were only achieved using lead dioxide and boron-doped diamond while Ti–Ru–Sn ternary oxide and platinum only permitted a partial oxidation of methyl red.
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influence of anode material on the electrochemical oxidation of 2 naphthol part 2 Bulk Electrolysis experiments
Electrochimica Acta, 2004Co-Authors: G CerisolaAbstract:Abstract The electrochemical oxidation of 2-naphthol has been studied by galvanostatic Electrolysis, using a range of electrode materials such as lead dioxide, boron-doped diamond (BDD) and Ti–Ru–Sn ternary oxide anodes. The influence of some operating parameters, such as current density, flow-rate and chloride concentration on naphthol oxidation has been investigated in order to find the optimum experimental conditions. Measurements of chemical oxygen demand, HPLC and total organic carbon have been used to follow the oxidation. The experimental data indicate that on PbO 2 and BDD, naphthol oxidation takes place by reaction with electrogenerated hydroxyl radicals and is favoured by low current density and high flow-rate. On the contrary, on a Ti–Ru–Sn ternary oxide the mineralisation of naphthol occurs only in the presence of chloride ions that act as redox mediators and COD removal is affected by chloride concentration and is not significantly influenced by the current density and mass-transfer coefficient. From a comparison of the results of the three electrodes it has been found that boron-doped diamond gives a faster oxidation rate and better current efficiency.
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electrochemical oxidation of phenol at boron doped diamond electrode
Electrochimica Acta, 2001Co-Authors: J Iniesta, P A Michaud, Marco Panizza, G Cerisola, A Aldaz, Ch. ComninellisAbstract:The electrochemical oxidation of phenol at synthetic boron-doped diamond thin film electrode (BDD) has been studied in acid media by cyclic voltammetry, chronoamperometry and Bulk Electrolysis. The results have shown that in the potential region of water stability (E 2.3 V vs. SHE), indirect oxidation reactions can take place by electrogenerated active intermediates, probably hydroxyl radicals, which can avoid electrode fouling. Depending on the values of applied current, and phenol concentration it is possible to obtain the complete combustion of phenol to CO2 or the partial oxidation of phenol to other aromatic compounds (benzoquinone, hydroquinone, catechol).
Marco Panizza - One of the best experts on this subject based on the ideXlab platform.
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Anodic oxidation of mecoprop herbicide at lead dioxide
Journal of Applied Electrochemistry, 2008Co-Authors: Marco Panizza, Ignasi Sirés, G CerisolaAbstract:The electrochemical oxidation of an aqueous solution containing mecoprop (2-(2-methyl-4-chlorophenoxy)propionic acid) has been studied at PbO_2 anodes by cyclic voltammetry and Bulk Electrolysis. The influence of current density, hydrodynamic conditions, temperature and pH on the degradation rate and current efficiency is reported. The results obtained show that the use of PbO_2 leads to total mineralization of mecoprop due to the production of oxidant hydroxyl radical electrogenerated from water discharge. The current efficiency for the electro-oxidation of mecoprop is enhanced by low current density, high recycle flow-rates and high temperature. In contrast, the pH effect was not significant. It has also been observed that mecoprop decay kinetics follows a pseudo-first-order reaction and the rate constant increases with rising current density.
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electrocatalytic materials for the electrochemical oxidation of synthetic dyes
Applied Catalysis B-environmental, 2007Co-Authors: Marco Panizza, G CerisolaAbstract:Abstract The electrocatalytic properties of Ti–Ru–Sn ternary oxide, platinum, lead dioxide and boron-doped diamond anodes for the oxidation of methyl red have been compared by potentiodynamic measurements and Bulk Electrolysis. The results of the cyclic voltammetries have shown that in the potential region of supporting electrolyte stability polymeric materials, which result in electrode deactivation, are formed on the electrode surfaces. While Ti–Ru–Sn ternary oxide and platinum cannot restore their initial activity by polarization, lead dioxide and boron-doped diamond anodes can be reactivated by Electrolysis in the potential region of electrolyte decomposition due to the electrogeneration of hydroxyl radicals. The Bulk Electrolysis showed that the complete COD and colour removal were only achieved using lead dioxide and boron-doped diamond while Ti–Ru–Sn ternary oxide and platinum only permitted a partial oxidation of methyl red.
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electrochemical oxidation of phenol at boron doped diamond electrode
Electrochimica Acta, 2001Co-Authors: J Iniesta, P A Michaud, Marco Panizza, G Cerisola, A Aldaz, Ch. ComninellisAbstract:The electrochemical oxidation of phenol at synthetic boron-doped diamond thin film electrode (BDD) has been studied in acid media by cyclic voltammetry, chronoamperometry and Bulk Electrolysis. The results have shown that in the potential region of water stability (E 2.3 V vs. SHE), indirect oxidation reactions can take place by electrogenerated active intermediates, probably hydroxyl radicals, which can avoid electrode fouling. Depending on the values of applied current, and phenol concentration it is possible to obtain the complete combustion of phenol to CO2 or the partial oxidation of phenol to other aromatic compounds (benzoquinone, hydroquinone, catechol).
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electrochemical oxidation of 3 methylpyridine at a boron doped diamond electrode application to electroorganic synthesis and wastewater treatment
Electrochemistry Communications, 2001Co-Authors: J Iniesta, P A Michaud, Marco Panizza, Ch. ComninellisAbstract:The electrochem. oxidn. of 3-methylpyridine (3-MP) at synthetic boron-doped diamond (BDD) thin film electrode was studied in acid media by cyclic voltammetry and Bulk Electrolysis. The results showed that in the potential region of water stability there can occur direct electron transfer reactions on BDD surface that result in electrode fouling due to the formation of a polymeric film on its surface. While during electrolyzes in the potential region of water decompn., indirect oxidn. reactions can take place by electrogenerated active intermediates, probably hydroxyl radicals that can avoid electrode fouling. Depending on the values of applied c.d., it is possible to obtain the partial oxidn. of 3-MP to nicotinic acid or the complete combustion of 3-MP to CO2. [on SciFinder (R)]
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electrochemical oxidation of 4 chlorophenol for wastewater treatment definition of normalized current efficiency ϕ
Journal of The Electrochemical Society, 2001Co-Authors: Leonardo Gherardini, P A Michaud, Marco Panizza, Christos Comninellis, Nicolaos VatistasAbstract:The electrochem. behavior of PbO2 and synthetic B-doped diamond thin film electrodes (BDDs) was studied in acid media contg. 4-chlorophenol (4-CP) by Bulk Electrolysis under different exptl. conditions. To quantify the electrochem. activity of a given electrode, for the electrochem. oxidn. of org. compds. (4-CP), the current efficiency of the anodic oxidn. was normalized taking into consideration mass-transport limitations. The normalized current efficiency (j) was defined as the ratio between the current efficiency of the investigated anode to the current efficiency of an ideal anode which has a very fast oxidn. rate, resulting in a complete combustion of orgs. to CO2. The results showed that even if the complete combustion of 4-CP was achieved at both PbO2 and BDD anodes, the latter give higher j. The difference in reactivity of the electrogenerated hydroxyl radicals on the anode surface, is proposed to explain the high j values obtained using B-doped diamond anodes. [on SciFinder (R)]
D. Klarup - One of the best experts on this subject based on the ideXlab platform.
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Degradation of terbutylazine (2-chloro-4-ethylamino-6-terbutylamino-1,3,5-triazine), deisopropyl atrazine (2-amino-4-chloro-6-ethylamino-1,3,5-triazine), and chlorinated dimethoxy triazine (2-chloro-4,6-dimethoxy-1,3,5-triazine) by zero valent iron a
Environmental Pollution, 2004Co-Authors: T. Dombek, D. Davis, J. Stine, D. KlarupAbstract:To help elucidate the mechanism of dechlorination of chlorinated triazines via metallic iron, terbutylazine (TBA: 2-chloro-4-ethylamino-6-terbutylamino-1,3,5-triazine), deisopropyl atrazine (DIA: 2-amino-4-chloro-6-ethylamino-1,3,5-triazine), and chlorinated dimethoxy triazine (CDMT: 2-chloro-4,6-dimethoxy-1,3,5-triazine) were degraded via zero valent iron under controlled pH conditions. The lower the solution pH the faster the degradation, with surface area normalized pseudo first order rate constants ranging from 2 (+/- 1)x10(-3) min(-1) m(-2) l for TBA at pH 2.0 to 4 (+/- 2)x10(-5) min(-1) m(-2) l for CDMT at pH 4.0. Hydrogenolysis (dechlorinated) products were observed for TBA and CDMT. Electrochemical reduction on mercury showed similar behavior for all of the triazines studied; the initial product of CDMT Bulk Electrolysis was the dechlorinated compound. The iron results are consistent with a mechanism involving the addition of surface hydrogen to the surface associated triazine.
