Array-type NH3 sensor
AssigneeUT-Battelle, LLC
InventorsDavid Lawrence West, Frederick Charles Montgomery, Timothy R. Armstrong, Robert J. Warmack
Life of this patent
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Abstract
An array-type sensor that senses NH3 includes non-Nernstian sensing elements constructed from metal and/or metal-oxide electrodes on an O2 ion conducting substrate. In one example sensor, one electrode may be made of platinum, another electrode may be made of manganese (III) oxide (Mn2O3), and another electrode may be made of tungsten trioxide (WO3). Some sensing elements may further include an electrode made of La0.6Sr0.4Co0.2Fe0.8O3 and another electrode made of LaCr0.95Mg0.05O3.
Claims22
A method of sensing ammonia (NH3) with an array-type sensor, the array-type sensor comprising a substrate that comprises an oxygen-ion conducting material, and an array of electrodes disposed on the substrate, the method comprising:
- operating a first electrode of the array of electrodes at a first temperature that is in a first temperature range, the first temperature range being from approximately 550-degrees Celsius to approximately 650-degrees Celsius, the first electrode comprising platinum (Pt);
- operating a second electrode of the array of electrodes at a second temperature that is in the first temperature range, the second electrode comprising manganese (III) oxide (Mn2O3);
- operating a third electrode of the array of electrodes at a third temperature that is in a second temperature range, the second temperature range being from approximately 650-degrees Celsius to approximately 750-degrees Celsius, the third electrode comprising tungsten trioxide (WO3);
- operating a fourth electrode of the array of electrodes at a fourth temperature that is in the second temperature range, the fourth electrode comprising La0.6Sr0.4Co0.2Fe0.8O3;
- operating a fifth electrode of the array of electrodes at a fifth temperature that is in the second temperature range, the fifth electrode comprising LaCr0.95Mg0.05O3;
- and
- sensing, with the array-type sensor, ammonia (NH3) in response to the first electrode operating at the first temperature, the second electrode operating at the second temperature, the third electrode operating at the third temperature, the fourth electrode operating at the fourth temperature, and the fifth electrode operating at the fifth temperature.
A method of sensing ammonia (NH3) in a selective catalytic reduction (SCR) subsystem of an exhaust system, the method comprising:
- positioning an array-type sensor at an output of the SCR subsystem, wherein the array-type sensor comprises a substrate that comprises an oxygen-ion conducting material, and an array of electrodes disposed on the substrate;
- operating a first set of electrodes of the array of electrodes at a first temperature that is in a first temperature range, the first temperature range being from approximately 550-degrees Celsius to approximately 650-degrees Celsius, wherein the first set of electrodes comprises a first electrode comprising platinum (Pt) and a second electrode comprising manganese (III) oxide (Mn2O3);
- operating a second set of electrodes of the array of electrodes at a second temperature that is in a second temperature range, the second temperature range being from approximately 650-degrees Celsius to approximately 750-degrees Celsius, the second set of electrodes comprising a third electrode comprising tungsten trioxide (WO3);
- a fourth electrode comprising La0.6Sr0.4Co0.2Fe0.8O3;
- and a fifth electrode comprising LaCr0.95Mg0.05O3;
- and
- sensing, with the array-type sensor positioned at the output of the SCR subsystem, ammonia (NH3) in response to the first set of electrodes operating at the first temperature and the second set of electrodes operating at the second temperature.
Dependencies are inferred from the claim text.