Electrochemical method for separating O2 from a gas; generating electricity; measuring O2 partial pressure; and fuel cell

Claim 1

A fuel cell comprising: a solid partition of a solid electrolyte consisting essentially of a solid solution of oxides having a high degree of oxygen ion conductivity compared with either electronic conductivity or cation conductivity, said solid electrolyte having the formula (MO.sub.2).sub.1-x (R.sub.y O.sub.z).sub.x where M represents at least one tetravalent element forming an oxide highly stable at temperatures of about 500°C to about 1200°C selected from the group consisting of zirconium, thorium and hafnium, R represents at least one element from the group consisting of elements of Groups II-A and III-B of the Periodic Table which form cations with stable +2 and +3 valences in the oxide, x represents a number having a value from about 0.05 to about 0.3 and y and z represent numbers having values necessary to make (R y O z ) electrically neutral; a first porous electrode consisting of lanthanum nickel oxide applied to a first face of said partition; a second porous electrode consisting of a mixture of nickel and platinum applied to the opposite face of said partition; said electrodes being stable at temperatures of about 500° C to about 1200° C; .[.mean.]. .Iadd.means .Iaddend.for supplying gas containing oxygen to said first electrode; means for supplying a fuel capable of reacting with oxygen on the opposite side of said partition near to said second electrode; means for heating said electrodes to an elevated temperature of about 500° C to 1200° C whereby oxygen forms ions at said first electrode which migrate through said partition upon placing it in a closed circuit and react with said fuel at the second electrode, said electrodes thereby developing a potential difference; and means for withdrawing the reaction products from near said second electrode.

Claim 5

A method for separating oxygen from a gas containing oxygen or for producing substantially pure oxygen comprising: supplying a gas containing oxygen to a first electrically conductive porous electrode of an electrochemical cell comprising a solid electrolyte consisting essentially of a solid solution of oxides having a high degree of oxygen ion conductivity compared with either electronic conductivity or cation conductivity, said solid electrolyte having the formula (MO 2 ) 1-x (R y O z ) x where M represents at least one tetravalent element from the group consisting of zirconium, thorium, valent element from the group consisting of zirconium, thorium, and hafnium, R represents at least one element from the group consisting of elements of Groups II-A and III-B of the Periodic Table which form cations with stable +2 and +3 valences in the oxide, x represents a number having a value of from about .[.0.05.]. .Iadd.0.1 .Iaddend.to about 0.3 and y and z represent numbers having values sufficient to make R y O z electrically neutral; said first electrically conductive porous electrode and a second electrically conductive porous electrode being disposed on opposite surfaces of said solid electrolyte; heating said electrolyte and electrodes, while supplying said gas, to a temperature within the range of from about 500°C to 1200°C; applying, while supplying said gas and heating said electrolyte and electrodes, a DC potential difference across said electrodes of a polarity such that said first electrode is negative with respect to said second electrode so that substantially pure oxygen is produced at said second electrode.

Claim 6

A method for separating oxygen from a gas containing oxygen or for producing substantially pure oxygen comprising: supplying a gas containing oxygen to a first electrically conductive porous electrode of an electrochemical cell comprising a solid electrolyte consisting essentially of a solid solution of oxides having a high degree of oxygen ion conductivity compared with either electronic conductivity or cation conductivity, said solid electrolyte having the formula (MO 2 ) 1-x (R y O z ) x where M represents at least one tetravalent element from the group consisting of zirconium, thorium, valent element from the group consisting of zirconium, thorium, and hafnium, R represents at least one element from the group consisting of elements of Groups II-A and III-B of the Periodic Table which form cations with stable +2 and +3 valences in the oxide, x represents a number having a value of from about .[.0.05.]. .Iadd.0.1 .Iaddend.to about 0.3 and y and z represent numbers having values sufficient to make R y O z electrically neutral; said first electrically conductive porous electrode and a second electrically conductive porous electrode being disposed on opposite surfaces of said solid electrolyte; heating said electrolyte and electrodes, while supplying said gas, to a temperature within the range of from about 500°C to 1200°C; applying, while supplying said gas and heating said electrolyte and electrodes, a DC potential difference across said electrodes of a polarity such that said first electrode is negative with respect to said second electrode so that substantially pure oxygen is produced at said second electrode.