PROCESS FOR COATING A POROUS ELECTRODE

摘要

Partial or complete surface coating of a porous electrode for electrochemical processes with an activating coating contg. Pt-gp. metals and cpds. involves applying soluble Pt metal cpd(s). and soluble Ti, Ta, Zr and/or Nb cpd(s). and a solvent to the electrode surface and thermal treatment. The novel features are that Ti, Ta, Zr or Nb chloride is dissolved in an alcohol and converted to an alcoholate; this is stirred in portions into an alcoholic soln. of a Pt metal chloride; the highly viscous soln. is applied to the electrode surface; the solvent is removed by evapn.; and the activating coating is formed by heating to 250-600 deg. C. The alcohol is EtOH, PrOH or BuOH; and the metal alcoholate pref. Ti ethanolate. The electrode is coated with a mixt. contg. 50-70% alcoholate and 50-30% Pt metal chloride soln., the mixt. having a viscosity of 0.01-0.1 Pa.s.