Cathode coating with hydrogen-evolution catalyst and semi-conducting polymer

Claim 1

A method of manufacturing a cathode comprising a catalytic coating for electrolytically evolving hydrogen formed on an electrically conductive electrode support, characterized by the steps of: (a) preparing a homogeneous coating solution containing on one hand a dissolved organic polymer precursor selected from the group consisting of: poly-p-phenylene, polyacrylonitrile, a prepolymer of polybenzimidazo-pyrrolone, and a prepolymer of an adamantane-based polybenzoxazole, and further containing on the other hand a dissolved inorganic precursor compound which can be thermally converted into a catalyst for evolving hydrogen; (b) applying said homogeneous coating solution in successive layers to said conductive electrode support; (c) drying each of said layers of the solution applied in step (b), thereby providing a coprecipitated intimate mixture of said catalyst precursor compound and said organic polymer precursor; and (d) subjecting each dried layer obtained in step (c) to heat treatment comprising at least one stage carried out in air at a temperature in the range from 200° C. to about 600° C., during 5 to 120 minutes, so as to thermally convert said organic polymer precursor to a semi-conducting insoluble polymer and said inorganic precursor compound to said catalyst for evolving hydrogen; thereby providing the cathode with a consolidated adherent catalytic coating in which said catalyst is finely dispersed and uniformly distributed throughout a matrix consisting of said semi-conducting insoluble polymer formed therewith in situ on said conductive electrode support.

Claim 2

A method of manufacturing a cathode comprising a catalytic coating for electrolytically evolving hydrogen formed on an electrically conductive electrode support, characterized by the steps of: (a) preparing a homogeneous coating solution containing on one hand a dissolved organic polymer precursor selected from the group consisting of: poly-p-phenylene, polyacrylonitrile, a prepolymer of polybenzimidazo-pyrrolone, and a prepolymer of an adamantane-based polybenzoxazole, and further containing on the other hand a dissolved inorganic precursor compound which can be thermally converted into a catalyst for evolving hydrogen; (b) applying said homogeneous coating solution in successive layers to said conductive electrode support; (c) drying each of said layers of the solution applied in step (b), thereby providing a coprecipitated intimate mixture of said catalyst precursor compound and said organic polymer precursor; and (d) subjecting each dried layer obtained in step (c) to heat treatment comprising at least one stage carried out in air at a temperature in the range from 200° C. to about 600° C., during 5 to 120 minutes, so as to thermally convert said organic polymer precursor to a semi-conducting insoluble polymer and said inorganic precursor compound to said catalyst for evolving hydrogen; thereby providing the cathode with a consolidated adherent catalytic coating in which said catalyst is finely dispersed and uniformly distributed throughout a matrix consisting of said semi-conducting insoluble polymer formed therewith in situ on said conductive electrode support.

Claim 10

A method of manufacturing a cathode for evolving hydrogen electrolytically and which comprises an electrically conductive substrate having an adherent electrocatalytic coating characterized by the steps of: (a) preparing a homogeneous coating solution comprising on the one hand a dissolved organic polymer precursor which can be thermally converted into a semi-conducting, insoluble polymer, and comprising on the other hand a dissolved inorganic precursor compound which can be thermally converted into an active catalyst for hydrogen evolution, and (b) applying said homogeneous coating solution to an electrically conductive valve metal substrate in successive layers each of which is individually dried and heat treated at temperatures in the range of about 200° C. to about 600° C. until said organic polymer precursor and said inorganic precursor compound have been converted to a semi-conducting polymer and said active hydrogen-evolving catalyst respectively; thereby providing on said valve metal substrate a consolidated adherent catalytic coating the active catalyst in which is finely dispersed and uniformly distributed throughout a matrix of said semi-conducting, insoluble polymer coformed in situ therewith.

Claim 11

A method of manufacturing a cathode for evolving hydrogen electrolytically and which comprises an electrically conductive substrate having an adherent electrocatalytic coating characterized by the steps of: (a) preparing a homogeneous coating solution comprising on the one hand a dissolved organic polymer precursor which can be thermally converted into a semi-conducting, insoluble polymer, and comprising on the other hand a dissolved inorganic precursor compound which can be thermally converted into an active catalyst for hydrogen evolution, and (b) applying said homogeneous coating solution to an electrically conductive valve metal substrate in successive layers each of which is individually dried and heat treated at temperatures in the range of about 200° C. to about 600° C. until said organic polymer precursor and said inorganic precursor compound have been converted to a semi-conducting polymer and said active hydrogen-evolving catalyst respectively; thereby providing on said valve metal substrate a consolidated adherent catalytic coating the active catalyst in which is finely dispersed and uniformly distributed throughout a matrix of said semi-conducting, insoluble polymer coformed in situ therewith.