A process for the increase in the catalytic aktivitaet of precious metal doped activated carbon for oxygen electrodes of electrochemical cells with an acidic electrolyte

摘要

Catalytical activity of active C doped with a noble metal for oxygen electrodes of fuel cells contg. an acid electrolyte is increased by impregnating pulverulent active C with a soln. of a noble metal salt, pref. a halide (-eg. PtCl4 or H2PtCl6.6H2O); reducing the salt (pref. with an aq. or alcoholic soln. of hydrazine, hydroxylamine, NaBH4, a formate etc., or with H2 at 100-300 degrees C); and activating the catalyst by treatment with e.g. NH3 at 900 degrees C. The prod. is compounded with a thermoplastic resin, pref. PTFE or polyethylene, to form an electrode. The efficiency of such an electrode is comperable with that of a pure-platinum electrode, while the consumption of the noble metal is very small (=0.8 mg/cm2).