Abstract: In a solid-oxide fuel cell assembly comprising a plurality of components having electrically-conductive mating surfaces therebetween, the surfaces are sealed by an electrically insulating gasket that include a mineral composition comprising about 66 mol % MgO and about 33 mol % SiO2, the mineral composition being known mineralogically as forsterite. A brazing alloy may be applied to enhance bonding of the gasket into place. The gasket composition may include additions of Al2O3 to enhance electrical resistivity while having little to no impact of matching expansion coefficients of the gasket and metal mating surfaces. Also, additions such as titania or zirconia to inhibit glassy phase grain boundaries and the formation of impurities and pores in the ceramic grain boundaries may be used. A recommended particle size distribution of precursor powders is disclosed that leads to an optimum microstructure of the sintered gasket.

Abstract: A method for manufacturing a planar sensor, comprises disposing a film of a material on a substrate, wherein the material is selected from the group consisting of platinum, rhodium, palladium and mixtures and alloys comprising at least one of the foregoing materials; annealing the material; measuring a resistance value of the material; laser trimming the annealed material; heat treating the laser trimmed material; and laser trimming the heat treated material to form the sensor.

Abstract: A sensor includes an oxygen pump cell; an oxygen pump chamber; an emf cell; a reference chamber providing a fluid connection to the reference gas; gas channels in fluid communication with the pump and emf electrodes, the reference gas comprising reformate produced by a fuel reformer fueled by an air-fuel gas mixture having an air-fuel ratio; a reformer electronic control module; a sensor electronic control module; a heater; a temperature sensor disposed in communication with the heater and the sensor control module for maintaining the sensor at a desired operating temperature; a closed loop controlled operation amplifier in electrical communication with the sensor, whereby the oxygen pump cell provides sufficient oxygen ions to oxidize an incoming diffusion-limiting fuel flux to the emf cell and maintain a constant emf at the emf cell, and wherein a current value represents an equivalent to the air-fuel ratio of the air-fuel gas mixture.

Abstract: In one embodiment, a gas sensor element comprises: an electrolyte disposed between and in ionic communication with a first electrode and a second electrode; and a protective layer disposed adjacent to the first electrode. The protective layer comprises a catalytic coating comprising a reducible support material, a catalyst, and a water activator material. The catalyst coating is capable of converting an oxygen consuming species in a gas to an oxygen donating species.

Abstract: Disclosed herein are methods of sensing NH3 in a gas and sensors therefore. In one embodiment, a method of sensing NH3 in a gas comprises: contacting a NOx electrode with the gas, and determining if a NOx emf between the NOx electrode and a reference electrode is greater than a selected emf. If the NOx emf is greater than the selected emf, a NH3 emf between an NH3 electrode and the reference electrode is determined. If the NOx emf is not greater than the selected emf, a NH3 emf between the NH3 electrode and the NOx electrode is determined.

Abstract: Disclosed herein are NOx sensors and methods of using the same. In one embodiment, a method for sensing NOx comprises: contacting a first NOx electrode with the gas, contacting a second NOx electrode with the gas, determining a NO2 emf between the first NOX electrode and a first reference electrode, determining a NOx emf between the second NOx electrode and a second reference electrode, and determining a NO2 concentration and a NO concentration using the NO2 emf and the NOx emf. The first electrode can be at a first temperature of greater than or equal to about 700 ° C., and the second electrode can be at a second temperature of about 500 ° C. to about 650 ° C.

Abstract: A sensor including a species selective electrode and a reference electrode having an electrolyte layer disposed therebetween; a reference gas channel in fluid communication with the reference electrode; a heater and a temperature sensor; wherein the species selective electrode is disposed on a first side of an insulating layer separating the species selective electrode from the electrolyte layer, the insulating layer having a first substantially solid area and a second area having an opening pattern extending through the insulating layer; the species selective electrode comprising a species sensing electrode portion disposed on the opening pattern of the insulating layer so as to contact the electrolyte layer through the opening pattern and a non-active electrode lead portion disposed over the first substantially solid area so that the non-active electrode lead portion is in electrical communication with the species sensing electrode portion and is free from contact with the electrolyte layer.

Abstract: Disclosed herein is a sensing element comprising: a sensing electrode; a reference electrode; an electrolyte disposed between and in ionic communication with the sensing electrode and the reference electrode; a heater circuit disposed on a support layer adjacent to the reference electrode; and a vent disposed adjacent to and in fluid communication with the heater circuit, and in fluid communication with a gas.

Abstract: Disclosed herein are electrochemical cells comprising a first electrode, a second electrode, and a solid oxide electrolyte disposed between and in ionic communication with the first electrode and the second electrode. The solid oxide electrolyte comprises the reaction product of a solid oxide electrolyte material, an aliovalent cation dopant, and a sintering aid selected from the group consisting of Al2O3, Ca2Al2O5, and combinations comprising at least one of the foregoing. The electrochemical cells can be utilized water electrolyzers, hydrogen pumps and for various gas sensing cells, SOFCs, and the like.

Abstract: One embodiment of an ammonia gas sensor includes: a reference electrode, an ammonia selective sensing electrode and an electrolyte disposed therebetween. The sensing electrode comprises the reaction product of a main material selected from the group consisting of vanadium, tungsten, molybdenum, vanadium oxides, tungsten oxides, molybdenum oxides, and combinations comprising at least one of the foregoing main materials, and an electrically conducting material selected from the group consisting of electrically conductive metals, electrically conductive metal oxides, and combinations comprising at least one of the foregoing.

Abstract: A gas sensing element and method of making are provided. The gas sensing element can comprise calcined inorganic oxides that sequester contaminants in an exhaust stream. The calcined inorganic oxides provide sensors with improved performance, thereby eliminating post-sinter chemical and/or electrical conditioning.

Abstract: A gas sensor system includes an ammonia-sensing cell for generating a signal upon exposure to an unknown gas comprising ammonia, an A/F cell for generating a signal upon exposure to hydrocarbons in the gas, a heater in thermal communication with the cells and a housing in which the cells and the heater are mounted. The housing permits an unknown gas to flow therethrough for contact with the cells, and there is a sensor control circuit in communication with the cells. The sensor control circuit is configured to utilize the signals from the cells to generate an ammonia concentration signal indicating the concentration of ammonia in the unknown gas. Ammonia may be sensed in an unknown gas by heating such cells to selected working temperatures, exposing them to an unknown gas, obtaining signals from the cells, and using the cell signals to determine the ammonia content.

Abstract: In a solid-oxide fuel cell assembly comprising a plurality of components having electrically-conductive mating surfaces therebetween, the surfaces are sealed by an electrically insulating gasket that include a mineral composition comprising about 66 mol % MgO and about 33 mol % SiO2, the mineral composition being known mineralogically as forsterite. A brazing alloy may be applied to enhance bonding of the gasket into place. The gasket composition may include additions of Al2O3 to enhance electrical resistivity while having little to no impact of matching expansion coefficients of the gasket and metal mating surfaces. Also, additions such as titania or zirconia to inhibit glassy phase grain boundaries and the formation of impurities and pores in the ceramic grain boundaries may be used. A recommended particle size distribution of precursor powders is disclosed that leads to an optimum microstructure of the sintered gasket.

Abstract: A method of making a sensor element comprises forming a sensor element comprising a first electrode and a second electrode disposed in physical communication with an electrolyte; and applying an electric field of negative potential to a surface of the sensor element sufficient to draw positively charged impurities to the surface of the sensing element.