Search results for "Electrolysi"
showing 10 items of 110 documents
Design of a LLC Resonant Converter for Powering a PEM Electrolyzer
2021
International audience; This paper proposes the design of a LLC resonant converter to supply a proton exchange membrane (PEM) electrolyzer. The PEM requires a low voltage with high current, a reduced output voltage ripple, and an overdamped dynamic behavior of the converter to avoid voltage overshoots. The designed converter allows satisfying the design constraints, minimizing switching and reverse recovery losses; the efficiency is influenced mainly by the output rectifier's conduction losses.
An impedance study of complex Al/Cu-Al2O3electrode
2011
Electrochemical impedance spectroscopy (EIS) was used to investigate different Cu deposition regimes on Al surface obtained by internal electrolysis and to characterize properties of fabricated electrodes. EIS experimental data confirmed that Cu deposition by internal electrolysis is realized and the complex electrode system is obtained. The main difficulty in preparation of Al/Cu electrodes is to prevent aluminium oxidation before and during electrochemical deposition of Cu particles. In this work NaCl, CH3COONa, K2SO4, mono- and diammonium citrate electrolytes were examined to determine their suitability for impedance measurements. Al/Cu-Al2O3 electrode composition was approved by equival…
Electrochemical incineration of 1,2-dichloroethane: Effect of the electrode material
2008
The electrochemical incineration of 1,2-dichloroethane (EDC) at Pt, Au, boron-doped diamond (BDD), Ebonex, stainless steel, Ti/IrO2–Ta2O5 and PbO2 has been studied in acid media by cyclic voltammetry and bulk electrolysis. It has been shown that the performances of the process dramatically depend on the anodic material. Higher current efficiencies were obtained at BDD. In particular, at proper values of applied current density, it is possible to obtain the almost complete conversion of EDC to CO2 at BDD with current efficiencies higher than 40%.
Electrochemistry as an Attractive and Effective Tool for the Synthesis and Immobilization of Porphyrins on an Electrode Surface
2014
Magnesium(II) 10-phenyl-5,15-p-ditolylporphyrin is easily and cleanly transformed by electrolysis. A nitro group is first introduced at the free meso position by anodic substitution. Hydrogenation into the amine is then carried out electrocatalytically under ambient conditions with water as a hydrogen supplier. The synthesized porphyrin under the nickel(II) form can be covalently grafted onto a platinum electrode by electrochemical reduction of the diazonium cation, generated in situ by a reaction of the nickel(II) aminoporphyrin with sodium nitrite and trifluoroacetic acid. The electrosynthesized thin film gives an electrochemical response typical of a porphyrin material. Films grown under…
Study of the Growth Mechanism of some Oxide Scales on Alloy 230 in High Temperature Vapor Electrolysis (HTVE) Conditions
2012
Alloy 230 (also named Haynes® 230) was tested as interconnect for production of hydrogen via High Temperature Vapor Electrolysis (HTVE). Samples were oxidized at 800°C in the both atmospheres representative of the HTVE operating conditions: Ar-1%H2-9%H2O (for cathode side) and air (for anode side). The high temperature oxidation behaviour was studied in both atmospheres together with the electrical conductivity of the thermally grown oxide scales. Oxidation kinetics indicated lower oxidation rate in H2/H2O compared to air (kp = 3.8 .10-15 g2.cm-4.s-1 in H2/H2O and kp = 1.6 .10-14 g2.cm-4.s-1 in air). The corrosion products were characterized by scanning electron microscopy associated with X…
Reaction Condition Screening by Using Electrochemical Microreactor: Application to Anodic Phenol-arene C,C Cross-Coupling Reaction in High Acceptor N…
2013
The anodic phenol-arene C,C cross-coupling reaction was achieved in inexpensive and sustainable media such as methanol, acetic acid, and formic acid by using an electrochemical microreactor which can provide a better performance to screen reaction conditions than in standard beaker-type electrolysis cells. Especially, formic acid as a reaction medium showed good performance. The total amount of cross-coupling product and homo-coupling products as a by-product was clearly increased as the solvent acceptor number increased. To control the selective oxidation of phenol, addition of methanol was effective.
Hydrogen from The Sea: The Challenge of the Future. Present and Future Developments
2014
In this paper we proposed the use of saline water to product hydrogen. As far as using saline water, can be proposed two different scheme and technology. The aim of this work is to design an electrolyze system capable of utilizing sea water for direct electrolysis. It is probable that these systems would operate at a low power density and electrolyze only a small portion of the water in contact with electrodes. In particular, we present the results obtained by two different prototype of electrolyzer: one with steel electrodes and the second electrodes with titanium. Further experiments were carried out by changing the electrolytic solution of water and sodium chloride in real seawater. Fina…
Electrolyses model development for metal/electrolyte interface: Testing with microrespiration sensors
2011
Abstract Initial process of electrolysis is investigated using platinum and tungsten wires as hydrogen electrodes and inductive kickback voltage peak based power unit. Microelectrodes are used to determine concentrations of dissolved hydrogen and pH close to wire electrodes. It is observed that concentration of dissolved hydrogen increases faster on tungsten electrode as on platinum. Authors explain this fact with differences of hydrogen evolution reaction on both materials – inductive kickback voltage peak power unit is supplying very short voltage pulses with limited energy what is enough only for hydrogen adsorption on platinum electrode, but is sufficient for full hydrogen evolution rea…
ChemInform Abstract: Synthesis of meta-Terphenyl-2,2′′-diols by Anodic C-C Cross-Coupling Reactions.
2016
The anodic C−C cross-coupling reaction is a versatile synthetic approach to symmetric and non-symmetric biphenols and arylated phenols. We herein present a metal-free electrosynthetic method that provides access to symmetric and non-symmetric meta-terphenyl-2,2′′-diols in good yields and high selectivity. Symmetric derivatives can be obtained by direct electrolysis in an undivided cell. The synthesis of non-symmetric meta-terphenyl-2,2′′-diols required two electrochemical steps. The reactions are easy to conduct and scalable. The method also features a broad substrate scope, and a large variety of functional groups are tolerated. The target molecules may serve as [OCO]3− pincer ligands.
The Pd3(dppm)3(CO)2+ Cluster: An Efficient Electrochemically Assisted Lewis Acid Catalyst for the Fluorination and Alcoholysis of Acyl Chlorides.
2002
The dicationic palladium cluster Pd3(dppm)3(CO)2+ (dppm = bis(diphenylphosphino)methane) reacts with acid chlorides RCOCl (R = n-C6H13, t-Bu, Ph) to afford quantitatively the chloride adduct Pd3(dppm)3(CO)(Cl)+ and the acyl cation RCO+ as the organic counterpart. The dicationic reactive cluster can be reformed by electrolyzing the chloride complex with a copper anode leaving CuCl as a byproduct. The combination of these two reactions provides an electrocatalytic way to form the acylium from the acid chloride. Indeed, in CH2Cl2, 0.2 M NBu4PF6, or NBu4BF4, the electrolysis of the acid chloride in the presence of a catalytic amount of the cluster (1%) gives in good yields the acid fluoride RCO…