Carbon dioxide gas sensors and method of manufacturing and using same
First Claim
1. A process for sensing carbon dioxide, including the following steps:
- applying a constant direct current voltage across a pair of electrodes, said electrodes being separated by an electrolyte material containing sodium, said electrodes located between a layer of Alumina substrate and a carbonate layer of auxiliary electrolyte, and, an extra layer of metal oxide selected from the group consisting of SnO2, In2O3, TiO2, WO3, ZnO, Fe2O3, ITO, CdO, U3O8, Ta2O5, BaO, MoO2, V2O5, Nb2O5, CuO, Cr2O3, La2O3, RuO3, RuO2, ReO2, ReO3, Ag2O, CoO, Cu2O, SnO, NiO, Pr2O3, BaO, PdO2, and HfO3 and mixtures thereof residing above and in engagement with said auxiliary electrolyte;
reacting carbon dioxide with said electrolyte material containing sodium at a first three-point boundary, said first three point boundary being at the joinder of one of said electrode, said electrolyte material containing sodium, and a barium containing auxiliary electrolyte;
reacting an oxide of sodium at a second three-point boundary, said second three-point boundary being at the joinder of the other of said electrodes, said electrolyte material containing sodium, and a barium containing auxiliary electrolyte;
measuring the resulting current; and
,correlating change in current to the concentration of carbon dioxide.
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Abstract
A gas sensor comprises a substrate layer; a pair of interdigitated metal electrodes, said electrodes include upper surfaces, the electrodes selected from the group consisting of Pt, Pd, Au, Ir, Ag, Ru, Rh, In, Os, and their alloys. A first layer of solid electrolyte staying in between electrode fingers and partially on said upper surfaces of said electrodes, said first layer selected from NASICON, LISICON, KSICON and β″-Alumina. A second layer of metal carbonate(s) as an auxiliary electrolyte engaging said upper surfaces of the electrodes and the first solid electrolyte. The metal carbonates selected from the group consisting of the following ions Na+, K+, Li+, Ag+, H+, Pb2+, Sr2+, Ba2+, and any combination thereof. An extra layer of metal oxide selected from the group consisting of SnO2, In2O3, TiO2, WO3, ZnO, Fe2O3, ITO, CdO, U3O8, Ta2O5, BaO, MoO2, MoO3, V2O5, Nb2O5, CuO, Cr2O3, La2O3, RuO3, RuO2, ReO2, ReO3, Ag2O, CoO, Cu2O, SnO, NiO, Pr2O3, BaO, PdO2, HfO3, HfO3 or other metal oxide and their mixtures residing above and in engagement with the second electrolyte to improve sensor performance and/or to reduce sensor heating power consumption.
18 Citations
21 Claims
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1. A process for sensing carbon dioxide, including the following steps:
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applying a constant direct current voltage across a pair of electrodes, said electrodes being separated by an electrolyte material containing sodium, said electrodes located between a layer of Alumina substrate and a carbonate layer of auxiliary electrolyte, and, an extra layer of metal oxide selected from the group consisting of SnO2, In2O3, TiO2, WO3, ZnO, Fe2O3, ITO, CdO, U3O8, Ta2O5, BaO, MoO2, V2O5, Nb2O5, CuO, Cr2O3, La2O3, RuO3, RuO2, ReO2, ReO3, Ag2O, CoO, Cu2O, SnO, NiO, Pr2O3, BaO, PdO2, and HfO3 and mixtures thereof residing above and in engagement with said auxiliary electrolyte; reacting carbon dioxide with said electrolyte material containing sodium at a first three-point boundary, said first three point boundary being at the joinder of one of said electrode, said electrolyte material containing sodium, and a barium containing auxiliary electrolyte; reacting an oxide of sodium at a second three-point boundary, said second three-point boundary being at the joinder of the other of said electrodes, said electrolyte material containing sodium, and a barium containing auxiliary electrolyte; measuring the resulting current; and
,correlating change in current to the concentration of carbon dioxide. - View Dependent Claims (2, 3)
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4. A gas sensor comprising:
- a substrate layer;
a pair of interdigitated metal electrodes each having a plurality of electrode fingers, said electrodes include upper surfaces, said electrodes, selected from the group consisting of Pt, Pd, Au, Ir, Ag, Ru, Rh, In, and Os, and alloys thereof;
a first layer of solid electrolyte staying in between electrode fingers and partially on said upper surfaces of said electrodes, said first layer selected from NASICON, LISICON, KSICON, and β
″
-Alumina;
a second layer of metal carbonate(s) as an auxiliary electrolyte engaging said upper surfaces of said electrodes and said first solid electrolyte;
said metal carbonates comprise an element selected from the group consisting of the following ions Na+, K+, Li+, Ag+, H+, Pb2+, Sr2+, Ba2+, and any combination thereof;
an extra layer of metal oxide selected from the group consisting of SnO2, In2O3, TiO2, WO3, ZnO, Fe2O3, ITO, CdO, U3O8, Ta2O5, BaO, MoO2, V2O5, Nb2O5, CuO, Cr2O3, La2O3, RuO3, RuO2, ReO2, ReO3, Ag2O, CoO, Cu2O, SnO, NiO, Pr2O3, BaO, PdO2, and HfO3 and mixtures thereof residing above and in engagement with said auxiliary electrolyte to improve sensor performance and/or to reduce sensor heating power consumption. - View Dependent Claims (5, 6)
- a substrate layer;
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7. A gas sensor comprising:
- a substrate layer;
a pair of interdigitated metal electrodes each having a plurality of electrode fingers, said electrodes include upper surfaces, said electrodes, selected from the group consisting of Pt, Pd, Au, Ir, Ag, Ru, Rh, In, and Os, and alloys thereof;
a first layer of solid electrolyte staying in between electrode fingers and partially on said upper surfaces of said electrodes, said first layer selected from NASICON, LISICON, KSICON, and β
″
-Alumina;
a second layer of metal carbonate(s) as an auxiliary electrolyte engaging said upper surfaces of said electrodes and said first solid electrolyte;
said metal carbonates comprise an element selected from the group consisting of the following ions Na+, K+, Li+, Ag+, H+, Pb2+, Sr2+, Ba2+, and any combination thereof;
an extra layer of metal oxide selected from the group consisting of SnO2, In2O3, TiO2, WO3, ZnO, Fe2O3, ITO, CdO, U3O8, Ta2O5, BaO, MoO2, V2O5, Nb2O5, CuO, Cr2O3, La2O3, RuO3, RuO2, ReO2, ReO3, Ag2O, CoO, Cu2O, SnO, NiO, Pr2O3, BaO, PdO2, and HfO3 and mixtures thereof mixed with Na2CO3/BaCO3 and residing above and in engagement with said auxiliary electrolyte to improve sensor performance and/or to reduce sensor heating power consumption. - View Dependent Claims (8)
- a substrate layer;
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9. A process for fabricating a carbon dioxide sensor including the following steps:
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depositing platinum interdigitated finger electrodes on a Alumina substrate, said electrodes having an upper surface; depositing solid electrolyte selected from the group of LISICON, KSICON, NASICON or and β
″
-Alumina between said finger electrodes and on a portion of said upper surface of said interdigitated finger electrodes; and
,depositing an auxiliary electrolyte material comprising a compound selected from the group consisting of Sodium Carbonate, Barium Carbonate, and mixtures thereof on top of the electrodes; and
,depositing an extra layer of metal oxide selected from the group consisting of SnO2, In2O3, TiO2, WO3, ZnO, Fe2O3, ITO, CdO, U3O8, Ta2O5, BaO, MoO2, V2O5, Nb2O5, CuO, Cr2O3, La2O3, RuO3, RuO2, ReO2, ReO3, Ag2O, CoO, Cu2O, SnO, NiO, Pr2O3, BaO, PdO2, and HfO3, and mixtures thereof residing above and in engagement with said auxiliary electrolyte to improve sensor performance and/or to reduce sensor heating power consumption. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21)
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Specification