A platinum coated titanium anode is an anode that synergistically combines the favorable electrochemical features of platinum (Pt) with the corrosion resistance and other characteristics of titanium.
Pt coated titanium anodes are produced by the electrochemical deposition of a thin layer of platinum metal or its oxides onto a titanium substrate. These anodes are very durable and are preferred because they remain insoluble in common electrolytes.
They are used as anodes in mercury cells and diaphragm cells for the production of chlorine and caustic alkali. In addition to being very durable, these anodes are economical because they can withstand high current densities without deteriorating.
Describes the process of coating a titanium support with platinum to provide an anode for use in cells for the electrolysis of aqueous solutions of alkali metal chlorides, particularly for use as an anode in a cell having a relatively large current density.
Example 1 illustrates an assembly comprising a surface of platinum borne on a supporting structure of titanium which has been prepared by coating the titanium support with an initial coating of a platinum-bearing preparation consisting of a thermally reducible platinum compound in an organic vehicle. The titanium support has then been dried and fired to give a deposit of platinum of 25 grams per square metre, calculated on the cell cathode area.
The platinum-coated titanium anode has been tested under actual service conditions in experimental mercury cells and diaphragm cells with a wide range of current densities. Under these circumstances, platinum consumption rates are very low, particularly when using concentrated NaCl solution. Under seawater (ten percent saturation), a platinum consumption rate of one microgram per ampere-hour has been recorded.