Oxygen sensor and emission control system
AssigneeGeorgia Tech Research Corporation
InventorsMeilin Liu, William Lynn Rauch, Zuoyan Peng
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Abstract
An emission control system is disclosed for determining a concentration of oxygen in a flow of gas which has a sensor. The sensor has a diffusion barrier, an electrolyte material, and a counter-electrode. The counter-electrode is configured to support the diffusion barrier, and the electrolyte material is disposed between the diffusion barrier and the counter electrode. Also disclosed is a method of producing the sensor and emission control system.
Claims21
A method of fabricating a gas sensor comprising:
- preparing a substrate, wherein the substrate also serves as a counter electrode;
- preparing an electrolyte material;
- depositing the electrolyte on the substrate;
- preparing an organic film on the surface of the electrolyte;
- preparing a diffusion barrier, wherein the diffusion barrier also serves as a sensing electrode and comprises a dense composite membrane consisting of yttria-stabilized zirconia and a noble metal;
- and
- depositing the diffusion barrier on the organic film.
A method of fabricating a gas sensor comprising:
- preparing a substrate, wherein the substrate also serves as a counter electrode;
- preparing an electrolyte material;
- depositing the electrolyte on the substrate;
- preparing an organic film on the surface of the electrolyte, wherein the step of preparing the organic film comprises:
- dissolving citric acid in ethylene glycol, with an approximate molar ratio of ethylene glycol to citric acid of 3;
- heating the resultant citric acid and ethylene glycol mixture to approximately 80° C. until the solution is viscous;
- preparing a diffusion barrier, wherein the diffusion barrier also serves as a sensing electrode;
- and
- depositing the diffusion barrier on the organic film.
A method of fabricating a gas sensor comprising:
- using a sol-gel process to prepare a first thin film comprising yttria-stabilized zirconia;
- depositing the first yttria-stabilized zirconia film on a layer of porous lanthanum strontium manganese oxide;
- depositing an organic film absent of metal ions on the surface of the first yttria-stabilized zirconia film;
- depositing a second film consisting of platinum and yttria-stabilized zirconia composite on the first yttria-stabilized zirconia film coated with the organic film;
- and
- firing the first and second films together.
A method of preparing an oxygen sensor comprising the steps of:
- preparing a diffusion barrier, wherein the diffusion barrier is a first electrode and wherein the diffusion barrier comprises platinum (Pt)-yttria-stabilized zirconia (YSZ), the Pt—YSZ composite comprising about 40% by volume Pt;
- pressing the diffusion barrier into a pellet;
- depositing mixed conducting oxide electrolyte powder on the diffusion barrier pellet followed by pressing;
- depositing a second electrode material onto pellet followed by pressing;
- and
- sintering of the diffusion barrier, electrolyte and second electrode to form a tri-layer oxygen sensor.
A method of preparing an oxygen sensor comprising the steps of:
- pressing an electrolyte material into a pellet with a top and bottom;
- depositing a layer of electrode material on top and bottom of the electrolyte pellet by pressing, wherein the electrode/electrolyte layers have a top and bottom;
- depositing a second layer of electrolyte material on both top and bottom of the electrode material, such that the layers have outer layers of electrolyte;
- firing the layers of electrolyte/electrode/electrolyte/electrode/electrolyte materials to form a multilayer structure;
- and
- grinding the multilayer structure to remove the outer electrolyte layers and expose the electrode layers.
Dependencies are inferred from the claim text.