| 摘要 |
An electrode for electrochemical cells is made by applying to an electrically conductive metal substrate either in situ or subsequently, a platinum-rhenium catalyst prepared by chemical coreduction from a solution of a platinum and a rhenium salt. The substrate may be a metal, e.g. platinum, or an organic membrane, glass or ceramic coated with electroconductive metal, e.g. gold. The reducing agent may be an alkali metal (preferably sodium) borohydride, hydrazine, hypophosphorous acid, sulphur dioxide, metal alkyls and silanes. The platinum and rhenium salts may be sodium or potassium perrhenate, rhenium trichloride or heptoxide, ammonium platino nitrate, dinitric diammino platinum, barium platino cyanide, sodium or ammonium chloroplatinate, potassium cyanoplatinate, platinum tetra- or trichloride, sodium bromoplatinate and potassium idoplatinate. When the catalyst is applied to the substrate subsequent to formation, it may be formed into a slurry with water applied, and then dried, or mixed with an organic binder, e.g. powdered P.T.F.E., polypropylene or carbon, applied and sintered. The catalyst may also contain nickel, vanadium or molybdenum prepared in a similar manner, i.e. by reduction of a salt. In an example: an aqueous solution of equal amounts of 0.5 moles Na2PtCl6 and 0.5 moles Re2O7 has an aqueou solution of sodium borohydride added to it. The resulting precipitated catalyst is pressed into an electrode comprising a platinum gauze welded to a platinum sheet. Other examples are described in which the catalyst is applied to a gold coated membrane.ALSO:An electrode for electrochemical cells is made by applying to an electrically conductive metal substrate either in situ or subsequently, a platinum-rhenium catalyst prepared by chemical coreduction from a solution of a platinum and a rhenium salt. The substrate may be a metal, e.g. platinum, or an organic membrane, glass or ceramic coated with electroconductive metal, e.g. gold. The reducing agent may be an alkali metal (preferably sodium) borohydride, hydrazine, hypophosphorous acid, sulphur dioxide, metal alkyls and silanes. The platinum and rhenium salts may be sodium or potassium perrhenate, rhenium, trichloride or heptoxide, ammonium platino nitrate, dinitric diammino platinum, barium platino cyanide, sodium or ammonium chloroplatinate, potassium cyanoplatinate, platinum tetra or trichloride, soduim bromoplatinate and potassium idoplatinate. When the catalyst is applied to the substrate subsequent to formation it may be formed into a slurry with water or mixed with an organic binder, e.g. powdered P.T.F.E., polypropylene or carbon. The catalyst may also contain nickel, vanadium or molybdenum prepared in a similar manner, i.e. by reduction from a salt. In an example: an aqueous solution of equal amounts of 0,5 moles Na2PtCl6 and 0,5 moles Re2O7 has an aqueous solution of sodium borohydride added to it. |
