Electrode with two layer coating, method of use, and preparation thereof
Systems and methods for manufacturing and use of a two layer coated electrode are provided. The two layer coated electrode may comprise a substrate, a first coating layer, and a second coating layer. The first coating layer may comprise a mixture of iridium oxide and tin oxide, and the second coating layer may comprise a mixture of iridium oxide and tantalum oxide. The electrode may be used in, for example, an electrolytic cell.
1. An electrode, comprising:
an electrically conductive substrate;
a first coating covering at least a portion of a surface of the electrically conductive substrate, the first coating consisting of a mixture of iridium oxide and tin oxide, having 45 wt. % to 65 wt. % iridium oxide; and
a second coating covering at least a portion of the first coating, the second coating consisting of a mixture of iridium oxide and tantalum oxide.
2. The electrode of claim 1 , wherein the electrically conductive substrate comprises a valve metal.
3. The electrode of claim 2 , wherein the valve metal is selected from the group consisting of titanium, zirconium, niobium, and tantalum.
4. The electrode of claim 3 , wherein the valve metal is titanium.
5. The electrode of claim 1 , wherein the second coating comprises 40 wt. % to 75 wt. % iridium oxide.
6. The electrode of claim 5 , wherein the second coating comprises 65 wt. % iridium oxide.
7. The electrode of claim 1 , wherein a molar ratio of iridium oxide in the first coating to the iridium oxide in the second coating is selected from the group consisting of 1:2, 1:1, and 2:1.
8. The electrode of claim 7 , wherein the molar ratio of iridium oxide in the first coating to the iridium oxide in the second coating is 1:1.
9. The electrode of claim 8 , wherein the electrode provides for a 175% longer normalized life than a reference electrode comprising a single layer coating consisting of a composition of the second coating,
wherein the normalized life is calculated by the following equation:
((x−y)/y)*100, where
x is the electrode's lifetime, and
y is the reference electrode's lifetime; and
lifetime is measured in A*hr/g Ir and determined by applying a constant current until a rise in voltage is measured.
10. The electrode of claim 8 , wherein the electrode provides for a 110% longer normalized life than a reference electrode comprising a single layer coating consisting of a composition of the first coating,
wherein the normalized life is calculated by the following equation:
((x−y)/y)*100, where
x is the electrode's lifetime, and
y is the reference electrode's lifetime; and
lifetime is measured in A*hr/g Ir and determined by applying a constant current until a rise in voltage is measured.
11. The electrode of claim 1 , wherein the electrode is an anode.
12. A system comprising an electrolytic cell, comprising:
an electrode comprising:
an electrically conductive substrate;
a first coating covering at least a portion of a surface of the electrically conductive substrate, the first coating consisting of a mixture of iridium oxide and tin oxide, having 45 wt. % to 65 wt. % iridium oxide; and
a second coating covering at least a portion of the first coating, the second coating consisting of a mixture of iridium oxide and tantalum oxide; and
a power source for supplying a current to the electrode.
13. The system of claim 12 , wherein the electrode is immersed in an electrolyte.
14. An electrode, comprising:
an electrically conductive substrate;
a first coating covering at least a portion of a surface of the electrically conductive substrate, the first coating consisting of a mixture of iridium oxide and tin oxide; and
a second coating covering at least a portion of the first coating, the second coating consisting of a mixture of iridium oxide and tantalum oxide, having 40 wt. % to 75 wt. % iridium oxide.
15. The electrode of claim 14 , wherein the electrically conductive substrate comprises a valve metal.
16. The electrode of claim 15 , wherein the valve metal is selected from the group consisting of titanium, zirconium, niobium, and tantalum.
17. The electrode of claim 16 , wherein the valve metal is titanium.
18. The electrode of claim 14 , wherein the first coating comprises 30 wt. % to 85 wt. % iridium oxide.
19. The electrode of claim 18 , wherein the first coating comprises 45 wt. % to 65 wt. % iridium oxide.
20. The electrode of claim 14 , wherein the second coating comprises 65 wt. % iridium oxide.
21. The electrode of claim 14 , wherein a molar ratio of iridium oxide in the first coating to the iridium oxide in the second coating is selected from the group consisting of 1:2, 1:1, and 2:1.
22. The electrode of claim 14 , wherein the electrode is an anode.
23. A system comprising an electrolytic cell, comprising:
an electrode comprising:
an electrically conductive substrate;
a first coating covering at least a portion of a surface of the electrically conductive substrate, the first coating consisting of a mixture of iridium oxide and tin oxide; and
a second coating covering at least a portion of the first coating, the second coating consisting of a mixture of iridium oxide and tantalum oxide, having 40 wt. % to 75 wt. % iridium oxide; and
a power source for supplying a current to the electrode.
24. The system of claim 23 , wherein the electrode is immersed in an electrolyte.