Permelec Electrode

The amphiphilic pyrrole is a fairly specialized application of ultrasound for the formation of a multiphase electrolyte system, but a more general case of ultrasonic assistance in both electrolyte formation and subsequent electrolysis is given in a recent Japanese patent by Permelec Electrode [235] in which benefit is claimed by use of a hydrophobic electrode to electrolyze poor water-soluble materials under ultrasound an aqueous emulsion. 

Japan Kokai Tokkyo Koho, JP 06 093 483. Nonaka, S., Kunngi, Y., Tei, Y., Watanabe N., assigned to Permelec Electrode. 

Development Department, Permelec Electrode Ltd, Kanagawa, Japan... 

The cell employed for the electrolytic production of NF3 was a cylindrical nickel cell of 1.5 dm in volume. A BDD with boron concentrations of 2500, 5000, 7500, 8000,10 000, and 12 500 ppm was used as the anode for the electrolytic production of NF3. For galvanostatic measurement of the anode polarization curve, a carbon anode (FE-5 Toyo Tanso Co., Ltd.) was also used in addition to the BDD anode. The BDD thin film (Permelec Electrode Ltd.) was prepared by the hot filament chemical vapor deposition (HFCVD) method on a carbon substrate using a gas mixture composed of CH4-H2-B(CH30)3-Ar. The anode was located at the center of the cell and the cell wall was utilized as the cathode. A nickel rod of 0.1 cm surface area pre-treated with anodic oxidation in a dehydrated NH4F-2HF melt was used as the reference electrode. The nickel rod functions as NiF Oy/Ni (0.073 V versus RHE) [4]. A PTFE skirt was provided between the anode and the cathode compartments, and the anode gas was separated from hydrogen evolved at the cathode to prevent an explosion. The cell bottom was covered with a PTFE sheet to avoid hydrogen evolution. 

Anode coating suppliers include Chemapol Industries (India), ELTECH (US), Electrode Products Inc. (US), DeNora (US), Huron (Canada), Permelec (Japan), INEOS (UK), Magneto-Chemie (Holland), Permelec (Italy), Team (India), Titan (India), and many others. 

As a general rule, these anodes are made from a titanium base metal covered by a rutile layer TiO doped by RuO (30 mol.%). They were used extensively in the industry (e.g., De Nora, Magnetochemie, Permelec, Eltech Systems Corp., US Filter, and Heraeus) and today they are used in all chlor-alkali processes and in chlorate production. The dimensionally stables anodes for chlorine evolution are described in the technical literature by the brand acronyms DSA (RuOj) and DSA -Cl2, and they enjoyed great success in industry for two reasons first, ruthenium has the lowest price of all the PGMs and, second, its density is half that of its neighbors. Moreover, its electrocatalytic characteristics for the evolution of chlorine are satisfactory. In industrial conditions (2 to 4 kA.m ) the service life of these electrodes is over 5 years. Therefore, today, titanium is the only base metal used for manufacturing dimensionally stable anodes for chlorine evolution. The contribution of Beer s discovery to the development of industrial electrochemistry is very important The reader can also find a complete story of the invention of DSA as told by the inventor himself and written on the occasion of his receiving the Electrochemical Society Medal award. 

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