Search results for "Electrolytic cell"
showing 9 items of 9 documents
A filter-press electrolytic cell with semi-continuous renewal of sacrifical electrodes
1989
Etude d'une cellule electrolytique dans laquelle une des electrodes est consummee avec remplacement de l'element sacrifie sans demontage de la cellule. Cette cellule est testee lors de l'electrocarboxylation de la N-phenylbenzalimine en acide amine
Simple and scalable electrochemical synthesis of 2,1-benzisoxazoles and quinoline N-oxides.
2019
Cathodic reduction of the nitro moiety and subsequent intramolecular cyclization affords different substituted 2,1-benzisoxazoles and quinoline N-oxides. This methodology allows the synthesis of two different types of heterocycles from common simple starting materials, using electrons as a sole reagent for this transformation. The electrolysis can be conducted in a very simple undivided electrolysis cell under constant current conditions. This permits working on a larger scale compared to other electrochemical methodologies and represents a significant advantage.
Enhancement of pulsed laser removal of metal oxides by electrochemical control
1996
Pulsed laser irradiation of oxidized metallic surfaces in an electrolytic cell under proper voltage conditions is demonstrated to be a promising new approach for effective removal of oxide films. Systematic measurements on simulated corrosion-product films by optical reflectance profile and energy dispersive X-ray spectroscopy are used to study the physical mechanisms of this novel phenomenon, the physical conditions for its observation and its possible generality. It was observed that the utilization of a basic electrolyte solution and the imposition of a certain cathodic potential prior to laser irradiation is an essential requirement for a high removal efficiency. This new technique has …
Development and Scale-Up of the Electrochemical Dehalogenation for the Synthesis of a Key Intermediate for NS5A Inhibitors
2015
The electrochemical 2-fold dehalogenation of a spirocyclopropane-proline derivative at leaded bronze was scaled-up in a divided batch-type electrolysis cell in good yield and excellent selectivity. The upscaling via a flow electrolysis cell was also successful. Conditions were elaborated employing a single cell passage for complete conversion. The keys here are the direct cooling of the cathode and ensuring a good laminar flow.
Electrodeposition methods in superheavy element chemistry
2008
To prepare electrodeposition experiments with superheavy elements (SHE), their homologs were investigated. In the experiments, various electrode materials and electrolytes were used. Critical potentials (E crit ) where the electrodeposition starts and potentials for the deposition of 50% of the atoms in solution (E 50% ) were determined. Underpotential deposition was observed in most cases. An electrolytic cell for a fast electrochemical deposition was developed and the time for the deposition of 50% of the atoms in solution (t 50% ) was determined. Short lived α-emitting isotopes were produced at Gesellschaft fur Schwerionenforschung (GSI), Darmstadt, transferred to the aqueous phase with …
Facile crosslinking of poly(vinylpyrrolidone) by electro-oxidation with IrO2-based anode under potentiostatic conditions
2018
Abstract: The modification of polymer architectures by reaction with chemically adsorbed hydroxyl radicals has been thoroughly investigated by electrolyzing dilute aqueous solutions of the biocompatible polymer poly(vinylpyrrolidone) (PVP), using an undivided electrolytic cell with a Ti/IrO2–Ta2O5(DSA®) anode. Several electrolyses were performed to assess the influence of the applied potential, the circulated charge and the PVP concentration, which was always kept low to avoid chain overlapping. From the results obtained, it can be concluded that the electro-oxidation of PVP solutions using a cheap anode is an effective method to crosslink initially isolated polymer chains, eventually incre…
A comparative evaluation of palladium and platinum nanoparticles as catalysts in proton exchange membrane electrochemical cells
2008
The goal of the present study is the development and comparative characterisation of carbon-supported and nanostructured Pd- and Pt-based electrocatalysts for hydrogen oxidation in Proton Exchange Membrane (PEM) H2/O2(air) fuel cells and proton reduction in PEM water electrolysers. Catalysts have been synthesised in a solution using a combined impregnation/reduction polyol method. They have been characterised using X-ray Diffraction (XRD) analysis, Transmission Electron Microscopy (TEM), Thermogravimetric Analysis (TGA) and cyclic voltammetry. NanoPt, nanoPd and nanoPt-Pd catalysts deposited onto a carbon carrier have been used to prepare Membrane-Electrode Assemblies (MEAs) which, in turn,…
Properties of amphiphilic terminally substituted conjugated nonaene- and 2-docosylnonaene carboxylic acids in monolayers at the air-water interface
1991
was a lo-' M Co(NO,), + lo-' M CH,COONa solution, with pH 7.5; the counter electrode was a Pt sheet, conveniently located in the electrochemical cell. After deposition, the electrochemical/electrochromic properties of the films were analyzed in degassed lo-' M KOH electrolyte, in a three electrode cell (Pt wire counter electrode, saturated calomel reference electrode) with optical windows. A PAR 173 potentiostat-galvanostat associated with a PAR 175 function generator was used in the electrochemical experiments. Data were recorded in a analogical X-Y (X-T) recorder. Monochromatic transmission (He-Ne laser, A = 632.8 nm) was recorded in situ, by means of a versatile optical bench; spectral t…
Experimental analysis of materials in proton exchange membrane electrolysis cells
2019
Abstract An accelerated supply and demand of energy has resulted in an increased need for efficient energy storage options, where storing energy in hydrogen gas emerges as one of the most attractive. In this study, a singular proton exchange membrane (PEM) electrolysis cell was designed using adequately low-cost materials, and tested using polarisation curves, cyclic voltammetry and AC impedance. A comparative study of various micro porous layer (MPL) materials was performed in an effort to find suitable options which are able to steadily operate under anodic conditions. The best performance was achieved using carbon cloth, however this material was unstable. Untreated porous titanium and n…