Abstract: A process of manufacturing a chabazite-type zeolite is provided having high heat resistance without having a large crystal size. A catalyst is also provided that contains such a chabazite-type zeolite and exhibits high nitrogen oxide reduction properties, and in particular high nitrogen oxide reduction properties in low temperatures below 200° C., even after exposure to high temperature and high humidity. A chabazite-type zeolite is provided having a silica to alumina molar ratio of no less than 15, a silanol group to silicon molar ratio of no more than 1.6×10?2, an average crystal size of 0.5 ?m to less than 1.5 ?m, and a ratio of 50%-volume particle size to 10%-volume particle size of no more than 3.2. The chabazite-type zeolite preferably contains at least one of copper and iron.

Abstract: A process of manufacturing a chabazite-type zeolite is provided having high heat resistance without having a large crystal size. A catalyst is also provided that contains such a chabazite-type zeolite and exhibits high nitrogen oxide reduction properties, and in particular high nitrogen oxide reduction properties in low temperatures below 200° C., even after exposure to high temperature and high humidity. A chabazite-type zeolite is provided having a silica to alumina molar ratio of no less than 15, a silanol group to silicon molar ratio of no more than 1.6×10?2, an average crystal size of 0.5 ?m to less than 1.5 ?m, and a ratio of 50%-volume particle size to 10%-volume particle size of no more than 3.2. The chabazite-type zeolite preferably contains at least one of copper and iron.

Abstract: A subject for the invention is to provide a chabazite-type zeolite that is expected to have durability and thermal resistance, which are practical properties required of catalyst supports and adsorbent bases, and that has profitability. A chabazite-type zeolite having an SiO2/Al2O3 molar ratio of 15-50 and an average particle diameter size of 1.5 ?m or more has high durability and high thermal resistance. Such a chabazite-type zeolite can be produced by crystallizing a starting-material composition in which the molar ratios of a structure-directing agent and water to SiO2 satisfy 0.05?(structure-directing agent)/SiO2<0.13 and 5?H2O/SiO2<30, in the presence of at least one kind of alkali metal ions selected from the group consisting of K, Rb, and Cs. The structure-directing agent preferably is an N,N,N-trimethyladamantaneammonium salt.

Abstract: The chabazite-type zeolite of the present invention has a SiO2/Al2O3 molar ratio of less than 15, and an average particle size from 1.0 ?m to 8.0 ?m. The chabazite-type zeolite of the present invention has excellent durability and heat resistance, and the copper-loaded chabazite-type zeolite has an improved NOx reduction rate at low temperatures compared to conventional copper-loaded chabazite-type zeolite.

Abstract: The invention relates to: a ?-type iron silicate which has a fluorine content not more than 400 ppm by weight on a dry basis and in which the crystal grains have a truncated square bipyramidal morphology in an examination with a scanning electron microscope and the whole or part of the iron is contained in the ?-type framework structure, and a process for producing the iron silicate; anther ?-type iron silicate, and a process for producing the iron silicate; and a nitrogen oxide removal catalyst containing the other ?-type iron silicate, a process for producing the catalyst, and a method for nitrogen oxide removal with the catalyst.

Abstract: The present invention relates to a composition including a ?-type iron silicate, which includes all or part of iron in a ?-type framework structure, and a solid acidic porous inorganic oxide. The present invention is characterized in that the ?-type iron silicate is compounded with the porous inorganic oxide having solid acidic properties so that the solid acidic function derived from aluminum of the ?-type iron silicate, is reinforced or complemented by the porous inorganic oxide, the individual particles of which are physically isolated from each other. It is preferred that the fluorine content relative to the dry weight of the ?-type iron silicate is 400 ppm or less and the crystal particles of the ?-type iron silicate have a truncated square bipyramidal morphology. According to the present invention, a composition that is useful as a high-performance catalyst, adsorbent, or the like, can be provided.

Abstract: An SCR catalyst using a ?-zeolite in which the molar ratio of SiO2/Al2O3 is from 20 to less than 40, the particle diameter determined by SEM is 0.35 ?m or more, the full width at half maximum (FWHM) of the X-ray diffraction peak for (302) is less than 0.30°, and the amount of adsorbed NH3 is 1 mmol/g or more, or has an amount of adsorbed NH3 following hydrothermal aging of 0.4 mmol/g or more, demonstrates high catalytic activity for NOx reduction at low temperatures following hydrothermal aging while also demonstrating a low level of discharge of irritating ammonia in exhaust gas.

Abstract: The present invention relates to a composition including a ?-type iron silicate, which includes all or part of iron in a ?-type framework structure, and a solid acidic porous inorganic oxide. The present invention is characterized in that the ?-type iron silicate is compounded with the porous inorganic oxide having solid acidic properties so that the solid acidic function derived from aluminum of the ?-type iron silicate, is reinforced or complemented by the porous inorganic oxide, the individual particles of which are physically isolated from each other. It is preferred that the fluorine content relative to the dry weight of the ?-type iron silicate is 400 ppm or less and the crystal particles of the ?-type iron silicate have a truncated square bipyramidal morphology. According to the present invention, a composition that is useful as a high-performance catalyst, adsorbent, or the like, can be provided.

Abstract: The chabazite-type zeolite of the present invention has a SiO2/Al2O3 molar ratio of less than 15, and an average particle size from 1.0 ?m to 8.0 ?m. The chabazite-type zeolite of the present invention has excellent durability and heat resistance, and the copper-loaded chabazite-type zeolite has an improved NOx reduction rate at low temperatures compared to conventional copper-loaded chabazite-type zeolite.

Abstract: The invention relates to: a ?-type iron silicate which has a fluorine content not more than 400 ppm by weight on a dry basis and in which the crystal grains have a truncated square bipyramidal morphology in an examination with a scanning electron microscope and the whole or part of the iron is contained in the ?-type framework structure, and a process for producing the iron silicate; anther ?-type iron silicate, and a process for producing the iron silicate; and a nitrogen oxide removal catalyst containing the other ?-type iron silicate, a process for producing the catalyst, and a method for nitrogen oxide removal with the catalyst.

Abstract: A subject for the invention is to provide a chabazite-type zeolite that is expected to have durability and thermal resistance, which are practical properties required of catalyst supports and adsorbent bases, and that has profitability. A chabazite-type zeolite having an SiO2/Al2O3 molar ratio of 15-50 and an average particle diameter size of 1.5 ?m or more has high durability and high thermal resistance. Such a chabazite-type zeolite can be produced by crystallizing a starting-material composition in which the molar ratios of a structure-directing agent and water to SiO2 satisfy 0.05?(structure-directing agent)/SiO2<0.13 and 5?H2O/SiO2<30, in the presence of at least one kind of alkali metal ions selected from the group consisting of K, Rb, and Cs. The structure-directing agent preferably is an N,N,N-trimethyladamantaneammonium salt.

Abstract: An SCR catalyst using a ?-zeolite in which the molar ratio of SiO2/Al2O3 is from 20 to less than 40, the particle diameter determined by SEM is 0.35 ?m or more, the full width at half maximum (FWHM) of the X-ray diffraction peak for (302) is less than 0.30°, and the amount of adsorbed NH3 is 1 mmol/g or more, or has an amount of adsorbed NH3 following hydrothermal aging of 0.4 mmol/g or more, demonstrates high catalytic activity for NOx reduction at low temperatures following hydrothermal aging while also demonstrating a low level of discharge of irritating ammonia in exhaust gas.