Gm Global Technolgoy Operations, Inc.

Delphi Technologies, Inc.

Earl Wayne Lankheet

Carlos Augusto Valdes

Jose P Joseph

Seajin Oh

Rick Daniel Kerr

Eric P Clyde

Frederick L Kennard

Fenglian Chang

Nancy Jean Paulus

Robert Gregory Fournier

David Thompson

Marsha E Nottingham

William John La Barge

William John Paulus

Frederick Lincoln Kennard, Iii

Venkatesh Rajagopalan

Tie Wang

Carilee E Cole

In one embodiment, a protective coating for an electrode of a sensor is described, the protective coating comprising an annealed catalyst, said annealed catalyst comprising at least one metal that has been subjected to thermal energy that is at least equivalent to or greater than that received from calcining the at least one metal for 24 hours at a temperature of 930 degrees C in air. In another embodiment, the annealed catalyst will comprise at least one metal that has been subjected to thermal energy that is equal to or less than that received from calcining the at least one metal for 24 hours at 1030 degrees C in air. In one exemplary embodiment, the annealed catalyst will comprise at least one metal that has been subjected to thermal energy that is equal to that received from calcining the at least one metal for 24 hours at 980 degrees C in air.

Catalyst anneal for durable stoichiometric shift corrected protective coating for oxygen sensors

A method for forming an electrode comprises: combining a platinum precursor with a gold precursor to form an electrode ink; forming the electrode ink into an electrode precursor; firing the electrode precursor to form the electrode; treating the electrode in an environment having an oxygen partial pressure of less than or equal to 500 ppm oxygen for a period of time sufficient produce an electrode with an exposed surface gold concentration of greater than or equal to about 6 times a bulk gold concentration in the electrode.

Methods of treating electrodes and gas sensors comprising the electrodes

Herein described is an exhaust gas sensor that is used to detect gas concentration in a &ldquo;lean only&rdquo; exhaust stream. The gas sensor comprises a single cell within a dielectric substrate. The cell has an electrolyte with an inner and outer electrode disposed against opposite sides of the electrolyte. A porous protective layer is disposed against the outer electrode. Gases can enter and exit the galvanic cell through the porous protective layer. A voltage is applied across the electrodes, and ions are actively pumped out of the cell. The applied current can be used to determine a specific gas concentration in the exhaust stream.

Simplified wide range air fuel ratio sensor

The present invention relates to an improved oxygen sensor and particularly to oxygen sensors used as exhaust sensors in vehicles. The oxygen sensor, which has an improved lean-rich response time and operability at lower temperatures, has been chemically etched and electrically treated, or chemically etched with a non-hydrofluoric acid solution.

Electrical and chemical treatment of an oxygen sensor

The invention includes the use of a pre-equilibration zone on an exhaust gas sensor to provide catalytic site to catalyze non-reacted components of the exhaust gas prior to the gas sample reaching the sensor's outer electrode. The pre-equilibration zone has microcomposite which preferably includes a precious metal in a porous carrier such as a ceramic oxide. The invention also includes a method of making an exhaust sensor including a pre-equilibration zone, and a method of sampling an exhaust gas by passing the same through a pre-equilibration zone.

Catalytic/ceramic oxide microcomposites for use as exhaust sensor

Generally, the instant invention includes a method of using a sensor having an outer electrode including a gold-containing layer to diagnose the efficiency and useful life of a catalytic converter. The sensor having a gold-containing layer is positioned in an exhaust gas, combustion engine downstream from both the engine and the catalytic converter used to clean the exhaust. The sensor produces an voltage output responsive to the combustibles concentration in the exhaust gas. The voltage output from the sensor is measured and compared to a predetermined threshold correlated to a desirable combustibles concentrations in the exhaust stream or to a threshold output indicative of an inefficiently operating catalytic converter. An electrical output is then provided which is responsive to the comparison. The electrical output may be an indicator light, gauge or other devices for instructing the operator of a vehicle that the catalytic converter requires maintenance. The gold-containing layer of the sensor may be a gold alloy containing at least 28 percent by weight gold. The gold-containing layer may be the sole outer electrode of the sensor, or the gold-containing layer may be formed on a conventional platinum electrode of the sensor.

Catalytic converter diagnostic sensor

A wide range oxygen sensor is provided which operates partially in the diffusion limited current mode to provide an output which is proportional to the oxygen partial pressure in a gas mixture which is sensed, such as the exhaust gas of an automotive internal combustion engine. The wide range oxygen sensor is constructed to have a planar structure with a single solid electrolyte layer that is shared by electrochemical storage, pumping and reference cells and which is deposited using known thermal deposition techniques. As a result, the wide range oxygen sensor of the present invention is characterized as being relatively low cost and readily producible under mass production conditions. Moreover, the wide range oxygen sensor is capable of rapidly and accurately sensing the exhaust gas oxygen partial pressure while the engine is operating in either the fuel-rich or fuel-lean condition to enable the evaluation of the air-to-fuel ratio of the precombustion fuel mixture.

Growing community of inventors

Grand Blanc, MI, United States of America

Earl Wayne Lankheet