Patent ID: 8211281
Filing Date: 2012-07-03
Classification: B01J,G01N

Abstract:
1. A sensor comprising: a sensing electrode having a first and second side and a first electrical lead in electrical communication with said sensing electrode; a reference electrode having a first and second side and a second electrical lead in electrical communication with said reference electrode; an electrolyte disposed between and in intimate contact with said first side of said sensing electrode and said first side of said reference electrode; and a first protective coating having a first and second side said first side disposed adjacent to said second side of said sensing electrode, said first coating formed by the process comprising the steps of: subjecting a mixture of a finely divided catalyst and a refractory metal oxide powder to a specific amount of thermal energy, the amount being either equal to or greater than that received from heating the metal catalyst for 24 hours at a temperature of 930 degrees C. for 24 hours in air but being no greater than that received from heating the metal catalyst for 24 hours at 1030 degrees C. in air, so as to produce an annealed catalyst having reduced catalytic activity relative to its catalytic activity before annealing; mixing the annealed catalyst with a first alumina slurry containing poison protective particles to provide an annealed catalyst slurry; applying the annealed catalyst slurry to said second side of said sensing electrode; and firing the applied annealed catalyst slurry at a temperature below the temperature used to anneal the catalyst by subjecting the applied annealed catalyst slurry to an amount of thermal energy being equal to or greater than that received by heating the applied annealed catalyst slurry to a temperature of 500 degrees C. for 1 hour but being no greater than that received from heating the applied annealed catalyst slurry to a temperature of 800 degrees C. for 4 hours.