Valve metal electrode with valve metal oxide semi-conductive coating having a chlorine discharge catalyst in said coating
AssigneeDiamond Shamrock Technologies S.A.
InventorsGiuseppe Bianchi, Vittorio DE Nora, Patrizio Gallone, Antonio Nidola
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Abstract
Describes chlorine resistant metal electrodes, preferably of valve metals such as titanium and tantalum, having coatings of mixed metal oxides, preferably valve metal oxides, which have been doped to provide semi-conducting surfaces on the electrodes, which coatings also have the capacity to catalyze chlorine discharge from the electrodes and to resist corrosive conditions in a chlorine cell.
Claims22
The method of effecting an electrolysis process in which an electrolysis current is passed through a halogen-containing electrolyte between an anode and a cathode and a halogen is released at the anode, which comprises passing the current through a valve metal base from the group consisting of titanium and tantalum, through an electrically conducting electrocatalytic coating on said valve metal base containing an electrocatalytic agent from the group consisting of rhenium, iron, manganese, zinc and the platinum group metals and up to 50% tin, said coating being in the form of oxides of said metals and said percentages being based upon the weight of the metals in said coating, and through the electrolyte to the cathode.
The method of effecting an electrolysis process in which an electrolysis current is passed through a halogen-containing electrolyte between an anode and a cathode and a halogen is released at the anode, which comprises passing the current through a valve metal base from the group consisting of titanium and tantalum, through an electrically conducting electrocatalytic coating on said valve metal base containing 39.2% to 78% of an oxide of titanium, 6.4% to 47.5% of an oxide of a platinum group metal and 1% to 17.7% of an oxide of a doping metal from the group consisting of tin, vanadium, lanthanum, cobalt, and mixtures thereof, the said percentages being based upon the weight of the metals in said oxides, and through the electrolyte to the cathode.
The method of effecting an electrolysis process in which an electrolysis current is passed through a halogen-containing electrolyte between an anode and a cathode and a halogen is released at the anode, which comprises passing the current through a valve metal base from the group consisting of titanium and tantalum, through an electrically conducting electrocatalytic coating on said valve metal base containing 39.2% to 78% of an oxide of titanium, 6.4% to 47.5% of at least one oxide of a platinum group metal and the remainder containing an oxide of tin and the oxide of one or more metals from the group consisting of tantalum, lanthanum, chromium, aluminum, iron, cobalt and nickel, the said percentages being based on the weight of the metals in said coating, said coating being in several layers on said valve metal base, and through the electrolyte to the cathode.
The method of effecting an electrolysis process in which an electrolysis current is passed through a halogen-containing electrolyte between an anode and a cathode and a halogen is released at the anode, which comprises passing the current through a valve metal base having a coating thereon containing at least three metal oxides, said oxides comprising 39% to 78% of an oxide of titanium, 16% to 47.5% of oxides of platinum group metals and 4% to 17.7% of an oxide selected from the group consisting of tin, vanadium, cobalt, and mixtures thereof, said percentages being based upon the weight of the metals in said oxides, and through the electrolyte to the cathode.
The method of effecting an electrolysis process in which an electrolysis current is passed through a halogen-containing electrolyte between an anode and a cathode and a halogen is released at the anode, which comprises passing the current through a chlorine resistant metal base having a semi-conductor coating thereon containing (a) a platinum group metal oxide, (b) titanium dioxide and (c) a doping oxide from the group consisting of oxides of tin, lanthanum, aluminum, cobalt, antimony, molybdenum, tungsten, tantalum, vanadium, phosphorus, boron, beryllium, sodium, calcium, strontium, and mixtures thereof, the titanium dioxide in said coating constituting more than 50% of the total metals in said coating, the platinum group metal oxide constituting from 16% to 47.5% of the total metals in said coating and the doping oxide constituting from 4% to 17.7% of the total oxides in said coating, and through the electrolyte to the cathode.
The method of effecting an electrolysis process in which an electrolysis current is passed through a halogen-containing electrolyte between an anode and a cathode and a halogen is released at the anode, which comprises passing the current through a chlorine resistant metal base from the group consisting of titanium and tantalum having a semi-conducting coating thereon containing an oxide of a platinum group metal in the amount of 6.4% to 47.5%, a material from the group consisting of titanium dioxide and tantalum pentoxide in the amount of 39.2% to 78% of said coating, said percentages being based upon the weight of the metals in said oxides, and at least one doping oxide from the group consisting of an oxide of silver, tin, chromium, lanthanum, aluminum, cobalt, antimony, molybdenum, nickel, iron, tungsten, vanadium, phosphorus, boron, beryllium, sodium, calcium, strontium, copper and bismuth, and mixtures thereof, the ratio of platinum group metals to the non-precious metals in said oxide coating being between 20:100 and 85:100, and through the electrolyte to the cathode.
The method of effecting an electrolysis process in which an electrolysis current is passed through a halogen-containing electrolyte between an anode and a cathode and a halogen is released at the anode, which comprises passing the current through a chlorine resistant metal base from the group cnsisting of titanium and tantalum, through a semi-conductor coating thereon containing (a) a metal oxide from the group consisting of ruthenium, iridium, palladium, osmium and rhenium in the amount of 6.4% to 47.5%, (b) a metal oxide from the group consisting of titanium dioxide or tantalum pentoxide in the amount of 39.2% to 78%, and (c) a doping oxide from the group consisting of oxides of silver, tin, chromium, lanthanum, aluminum, cobalt, antimony, molybdenum, nickel, iron, tungsten, vanadium, phosphorus, boron, beryllium, sodium, calcium, strontium, copper and bismuth, and mixtures thereof, the amount of 1% to 30%, the percentage of doping oxide being between 0.10% and 50% of the metal oxide from the group consisting of titanium dioxide and tantalum pentoxide and the ratio of platinum group metals to the non-precious metals in said oxide coatings being between 20:100 and 85:100, all said percentages being based upon the weight of the metal in said oxides, and through the electrolyte to the cathode.
The method of effecting an electrolysis process in which an electrolysis current is passed through a halogen-containing electrolyte between an anode and a cathode and a halogen is released at the anode, which comprises passing the current through a chlorine resistant metal base from the group consisting of titanium and tantalum, through a semi-conductor coating thereon containing (a) ruthenium oxide, (b) titanium dioxide and (c) at least one doping oxide from the group consisting of oxides of tantalum, tin, lanthanum, cobalt, nickel, iron, vanadium and aluminum, and mixtures thereof, and through the electrolyte to the cathode.
Dependencies are inferred from the claim text.