PRODUCTION OF GAS DIFFUSING ELECTRODE

摘要

PURPOSE:To obtain a gas diffusing electrode having large current quantity per unit area by sticking a platinum group metal, etc., to a sheet which is formed by impregnating a solvent to cake to make the sheet easily moldable and contains hydrophilic carbon black so that an electrolyte contacts with the entire platinum in a reaction layer without generating platinum group-contg. scrap. CONSTITUTION:A mixture composed of both hydrophilic and water repellent carbon blacks water and polytetrafluoroethylene and mixture composed thereof except the polytetrafluoroethylene are respectively filtered and the cake is prepd. A solvent such as ethanol is penetrated into both cake and after the cake is rolled to a required thickness, the rolled cake is heated to prepare sheets 6, 6'. Both sheets are heated after the prepn. and are joined under the pressure. A soln. 7 of the platinum group compd. such as PdCl is then impregnated to the hydrophilic carbon black-contg. sheet 6 and is decomposed by heating to stick the platinum group metal such as Pd or the oxide thereof or both thereof the hydrophilic part. The above-mentioned electrode 10 having the reaction layer 8 consisting of the hydrophilic part and water repellent part and the water repellent gas diffusing layer 9 is thus obtd.