Abstract: The present invention provides an exhaust gas purification catalyst having an excellent purification performance for purifying chemically stable methane. A catalyst material 30 includes a carrier 32 formed of alumina and a catalyst 34 formed of at least one of palladium and a palladium oxide directly supported on the carrier 32. A specific surface area of the carrier 32 is preferably 20 m2/g or more 90 m2/g or less. In one preferred aspect, a proportion of Pd(100) and PdO(101) in crystal planes of the catalyst 34 at a joint surface between the catalyst 34 and the carrier 32 is 20 number % or more.

Abstract: In an ammonia sensor (1), lead portions (7) and (9) are provided on an insulating substrate (5); a pair of comb-shaped electrodes (11) and (13) are connected to the lead portions (7) and (9), respectively; a sensitive layer (15) is provided on the comb-shaped electrodes (11) and (13); and a protective layer (17) is provided on the sensitive layer (15). Particularly, the sensitive layer (15) is formed of a gas-sensitive raw material predominantly containing ZrO2 and containing at least W in an amount of 2 to 40 wt. % as reduced to WO3.

Abstract: In an ammonia sensor (1), lead portions (7) and (9) are provided on an insulating substrate (5); a pair of comb-shaped electrodes (11) and (13) are connected to the lead portions (7) and (9), respectively; a sensitive layer (15) is provided on the comb-shaped electrodes (11) and (13); and a protective layer (17) is provided on the sensitive layer (15). Particularly, the sensitive layer (15) is formed of a gas-sensitive raw material predominantly containing ZrO2 and containing at least W in an amount of 2 to 40 wt. % as reduced to WO3.

Abstract: Nitrous oxide contained in a gas is directly decomposed by contacting the gas with a catalyst layer composed mainly of tin (IV) oxide at a reaction temperature of not less than 250.degree. C., preferably not less than 300.degree. C. Particularly when a cobalt (II) compound is added to the catalyst layer, nitrous oxide can be effectively removed to a low concentration by contacting the gas with the catalyst layer at the reaction temperature of not less than 200.degree. C., preferably not less than 300.degree. C. By the present process, nitrous oxide which has not conventionally effectively removed can be reliably removed at a low cost. The present process can be applied for the removal of nitrous oxide in exhaust gases discharged from a sludge-incinerating furnace, a boiler fine powder coal combustion furnace, etc.