Catalysts Having Mixed Metal Oxides

Abstract

Disclosed are methods for generating oxygen via an electrolysis reaction. One places an anode and a cathode in aqueous solution, and uses an external source of electricity to drive the electrolysis reaction from the anode and cathode. The anode has at least three metal oxides, preferably with nickel oxide or cobalt oxide as at least one of the oxides. Also disclosed are electrodes designed for catalyzing oxygen consumption or formation reactions, where the electrodes have a mix of such three metal oxides.

We claim: 
     
         1 . A method for generating oxygen via an electrolysis reaction, comprising:
 placing an anode and a cathode in aqueous solution; and   using an external source of electricity to drive the electrolysis reaction from the anode and cathode;   wherein the anode comprises at least three metal oxides selected from the group consisting of:   (a) nickel oxide or cobalt oxide as a first oxide, aluminum oxide or gallium oxide as a second oxide, and iron oxide or chromium oxide as a third oxide;   (b) nickel oxide, iron oxide, and a third oxide selected from the group consisting of barium oxide, cerium oxide, calcium oxide, gallium oxide, magnesium oxide and strontium oxide;   (c) nickel oxide, cobalt oxide, and a third oxide selected from the group consisting of barium oxide, calcium oxide, chromium oxide, strontium oxide and zinc oxide;   (d) nickel oxide, chromium oxide, and a third oxide selected from the group consisting of aluminum oxide, titanium oxide and zinc oxide;   (e) nickel oxide, calcium oxide, and a third oxide selected from the group consisting of aluminum oxide, strontium oxide and barium oxide; and   (f) cobalt oxide, aluminum oxide, and a third oxide selected from the group consisting of barium oxide and bismuth oxide;   whereby oxygen is generated.   
     
     
         2 . The method of  claim 1 , wherein the anode comprises aluminum oxide and iron oxide. 
     
     
         3 . The method of  claim 1 , wherein a metal oxide portion of the anode comprises at least 5% by weight of aluminum oxide and/or gallium oxide, at least 5% by weight of iron oxide and/or chromium oxide, and at least 5% by weight of cobalt oxide and/or nickel oxide. 
     
     
         4 . The method of  claim 1 , wherein hydrogen is generated at the cathode, and oxygen is generated at the anode. 
     
     
         5 . The method of  claim 1 , wherein the aqueous solution is alkaline. 
     
     
         6 . An electrode configured for catalyzing oxygen gas formation or consumption, the electrode comprising at least three metal oxides selected from the group consisting of:
 (a) nickel oxide or cobalt oxide as a first oxide, aluminum oxide or gallium oxide as a second oxide, and iron oxide or chromium oxide as a third oxide;   (b) nickel oxide, iron oxide, and a third oxide selected from the group consisting of barium oxide, cerium oxide, calcium oxide, gallium oxide, magnesium oxide and strontium oxide;   (c) nickel oxide, cobalt oxide, and a third oxide selected from the group consisting of barium oxide, calcium oxide, chromium oxide, strontium oxide and zinc oxide;   (d) nickel oxide, chromium oxide, and a third oxide selected from the group consisting of aluminum oxide, titanium oxide and zinc oxide;   (e) nickel oxide, calcium oxide, and a third oxide selected from the group consisting of aluminum oxide, strontium oxide and barium oxide; and   (f) cobalt oxide, aluminum oxide, and a third oxide selected from the group consisting of barium oxide and bismuth oxide.   
     
     
         7 . The electrode of  claim 6 , wherein the electrode comprises aluminum oxide and iron oxide. 
     
     
         8 . The electrode of  claim 6 , wherein a metal oxide portion of the electrode comprises at least 5% by weight of aluminum oxide and/or gallium oxide, at least 5% by weight of iron oxide and/or chromium oxide, and at least 5% by weight of cobalt oxide and/or nickel oxide. 
     
     
         9 . The electrode of  claim 6 , wherein at least one of the oxides was formed from a nitrate salt subjected to calcination.