Abstract: A catalyst for purifying NOx is provided which efficiently decomposes and purify the NOx in an exhaust gas in an oxygen-excess atmosphere, excels in resistance to heat and in durability in a high temperature range under a high-temperature oxidizing atmosphere and in the presence of moisture and SOx, and manifests the catalytic activity over a wide range of temperature. It is a catalyst for purifying nitrogen oxides formed by coating (A) a catalytically active component comprising (A-a) iridium and (A-b) at least one element selected from the group consisting of the elements of Group IIIA and Group IVA in the Periodic Table of the Elements with (B) a refractory inorganic compound.

Abstract: During the deposition of a catalytic component on a carrier, the position of the liquid level of a slurry containing the catalytic component is controlled with high accuracy and the adhesion of the slurry to the lateral face of the carrier is prevented. In the deposition of the liquid substance on the carrier by the introduction of the liquid substance into the carrier from the bottom face thereof, the liquid level near the top face of the carrier is detected by an image-processing sensor.

Abstract: A catalytically active component is deposited exclusively on a carrier component by utilizing a container-integrated carrier. Prior to the deposition of the active component on the carrier, the carrier is sealed and then the deposition of the active component is performed.

Abstract: An exhaust gas purifying catalyst having a refractory three-dimensional structure coated with a catalytically active component comprising at least one kind of noble metals, a refractory inorganic oxide, and a zirconium oxide containing cerium and lanthanum, the crystal structure of the zirconium oxide containing cerium and lanthanum being a tetragonal structure of zirconium oxide.

Abstract: A catalyst for purifying NOx is provided which efficiently decomposes and purify the NOx in an exhaust gas in an oxygen-excess atmosphere, excels in resistance to heat and in durability in a high temperature range under a high-temperature oxidizing atmosphere and in the presence of moisture and SOx, and manifests the catalytic activity over a wide range of temperature. It is a catalyst for purifying nitrogen oxides formed by coating (A) a catalytically active component comprising (A-a) iridium and (A-b) at least one element selected from the group consisting of the elements of Group IIIB and Group IVB in the Periodic Table of the Elements with (B) a refractory inorganic compound.

Abstract: During the deposition of a catalytic component on a carrier, the position of the liquid level of a slurry containing the catalytic component is controlled with high accuracy and the adhesion of the slurry to the lateral face of the carrier is prevented. In the deposition of the liquid substance on the carrier by the introduction of the liquid substance into the carrier from the bottom face thereof, a water-detecting sensor detects the liquid level near the top face of the carrier.

Abstract: A catalytic apparatus for exhaust purification, provided in an exhaust path of an internal-combustion engine operable with at least a theoretical air-fuel ratio and a lean air-fuel ratio, is provided with a three-way catalyst (4) having an inner layer (12a) thereof mainly containing rhodium as a noble metal to be activated in an oxygen concentration lowering atmosphere and a surface layer (12b) thereof mainly containing platinum or palladium as a noble metal to be activated in an oxygen concentration increasing atmosphere. In the catalytic apparatus, platinum or palladium in the surface layer is activated in lean operation to perform an HC purifying function effectively. If oxygen is temporarily in short supply during the change from a lean air-fuel ratio of exhaust gas over to a stoichiometric air-fuel ratio, oxygen is supplemented to purify HC by utilizing the O2 storage function of platinum or palladium as the noble metal, whereby the HC purifying rate can be prevented from temporarily suddenly lowering.

Abstract: A catalytically active component is deposited exclusively on a carrier component by utilizing a container-integrated carrier. Prior to the deposition of the active component on the carrier, the carrier is sealed and then the deposition of the active component is performed.

Abstract: During the deposition of a catalytic component on a carrier, the position of the liquid level of a slurry containing the catalytic component is controlled with high accuracy and the adhesion of the slurry to the lateral face of the carrier is prevented. In the deposition of the liquid substance on the carrier by the introduction of the liquid substance into the carrier from the bottom face thereof, a water-detecting sensor detects the liquid level near the top face of the carrier.

Abstract: During the deposition of a catalytic component on a carrier, the position of the liquid level of a slurry containing the catalytic component is controlled with high accuracy and the adhesion of the slurry to the lateral face of the carrier is prevented. In the deposition of the liquid substance on the carrier by the introduction of the liquid substance into the carrier from the bottom face thereof, the liquid level near the top face of the carrier is detected by an image-processing sensor.

Abstract: An exhaust gas purifying catalyst having a refractory three-dimensional structure coated with a catalytically active component comprising at least one kind of noble metals, a refractory inorganic oxide, and a zirconium oxide containing cerium and lanthanum, the crystal structure of the zirconium oxide containing cerium and lanthanum being a tetragonal structure of zirconium oxide.

Abstract: A purifying catalyst for the exhaust gas from the internal combustion engine of an automobile, for example, is disclosed which excels in the purifying ability in quick response to the atmosphere of the exhaust gas largely varying with changes in the operating condition of the engine involving such phases as idling, acceleration, constant-speed drive, and deceleration. The purifying catalyst contains rhodium, palladium, a cerium compound, and a refractory inorganic oxide as catalytic components carried on a refractory carrier and comprises at least two catalyst layers, namely a catalyst layer containing the cerium compound and a catalyst layer containing palladium.