A dehydrogenation catalyst for producing propylene by a dehydrogenation reaction of propane, the dehydrogenation catalyst including a platinum element and an element M1 and may contain an element M2 as active components, wherein the element M1 is one or more elements selected from the group consisting of a gallium element, a cobalt element, a copper element, a germanium element, a tin element and an iron element, the element M2 is one or more elements selected from the group consisting of a lead element and a calcium element, and the platinum element and the element M1 form an alloy.

The present invention provides a method of producing a honeycomb structured body having excellent mechanical strength. The present invention relates to a method of producing a honeycomb structured body including a honeycomb fired body in which multiple through-holes are arranged longitudinally in parallel with one another with a partition wall therebetween, the method including: a raw material mixing step of preparing a raw material paste containing ceria-zirconia composite oxide particles, alumina particles, an inorganic binder, and alumina fibers; a molding step of molding the raw material paste into a honeycomb molded body in which multiple through-holes are arranged longitudinally in parallel with one another with a partition wall therebetween; a drying step of drying the honeycomb molded body obtained in the molding step; and a firing step of firing the honeycomb molded body dried in the drying step into a honeycomb fired body, wherein the percentage of amorphous alumina fibers in the alumina fibers for use in the raw material mixing step is 50 to 100 wt %.

The present invention provides a method of producing a honeycomb structured body having excellent mechanical strength. The present invention relates to a method of producing a honeycomb structured body including a honeycomb fired body in which multiple through-holes are arranged longitudinally in parallel with one another with a partition wall therebetween, the method including: a raw material mixing step of preparing a raw material paste containing ceria-zirconia composite oxide particles, alumina particles, an inorganic binder, and alumina fibers; a molding step of molding the raw material paste into a honeycomb molded body in which multiple through-holes are arranged longitudinally in parallel with one another with a partition wall therebetween; a drying step of drying the honeycomb molded body obtained in the molding step; and a firing step of firing the honeycomb molded body dried in the drying step into a honeycomb fired body, wherein the percentage of amorphous alumina fibers in the alumina fibers for use in the raw material mixing step is 50 to 100 wt %.

The present invention provides a method of producing a honeycomb structured body having excellent mechanical strength. The present invention relates to a method of producing a honeycomb structured body including a honeycomb fired body in which multiple through-holes are arranged longitudinally in parallel with one another with a partition wall therebetween, the method including: a raw material mixing step of preparing a raw material paste containing ceria-zirconia composite oxide particles, alumina particles, an inorganic binder, and inorganic fibers; a molding step of molding the raw material paste into a honeycomb molded body in which multiple through-holes are arranged longitudinally in parallel with one another with a partition wall therebetween; a drying step of drying the honeycomb molded body obtained in the molding step; and a firing step of firing the honeycomb molded body dried in the drying step into a honeycomb fired body, wherein the raw material mixing step includes pre-mixing of the inorganic binder and the inorganic fibers.

The present invention provides a method of producing a honeycomb structured body having excellent mechanical strength. The present invention relates to a method of producing a honeycomb structured body including a honeycomb fired body in which multiple through-holes are arranged longitudinally in parallel with one another with a partition wall therebetween, the method including: a raw material mixing step of preparing a raw material paste containing ceria-zirconia composite oxide particles, alumina particles, an inorganic binder, and inorganic fibers; a molding step of molding the raw material paste into a honeycomb molded body in which multiple through-holes are arranged longitudinally in parallel with one another with a partition wall therebetween; a drying step of drying the honeycomb molded body obtained in the molding step; and a firing step of firing the honeycomb molded body dried in the drying step into a honeycomb fired body, wherein the raw material mixing step includes pre-mixing of the inorganic binder and the inorganic fibers.

The exhaust gas purification device includes a substrate, a first catalyst layer, and a second catalyst layer. The substrate includes an upstream end, a downstream end, and a porous partition wall defining a plurality of cells extending between the upstream end and the downstream end. The plurality of cells include an inlet cell opening at the upstream end and sealed at the downstream end, and an outlet cell adjacent to the inlet cell sealed at the upstream end and opening at the downstream end. The first catalyst layer is disposed on a surface of the partition wall in an upstream region. In a downstream region, the second catalyst layer is disposed inside the partition wall, and a second catalyst-containing wall including the partition wall and the second catalyst layer has a porosity of 35% or more.

A cerium-zirconium-aluminum-based composite material, a cGPF catalyst and a preparation method thereof are provided. The cerium-zirconium-aluminum-based composite material adopts a stepwise precipitation method, firstly preparing an aluminum-based pre-treated material, then coprecipitating the aluminum-based pre-treated material with zirconium and cerium sol, and finally roasting at high temperature to obtain the cerium-zirconium-aluminum-based composite material. The cerium-zirconium-aluminum-based composite material has better compactness and higher density, and when it is used in cGPF catalyst, it occupies a smaller volume of pores on the catalyst carrier, such that cGPF catalyst has lower back pressure and better ash accumulation resistance, which is beneficial to large-scale application of cGPF catalyst.

An object of the present invention is to provide means for releasing oxygen at a temperature lower than conventional means in an exhaust gas purification catalyst. A Ce—Zr composite oxide is provided, which has a crystallite diameter of 6.5 nm or less and a BET specific surface area of 90 m.sup.2/g or more.

An object of the present invention is to provide means for releasing oxygen at a temperature lower than conventional means in an exhaust gas purification catalyst. A Ce—Zr composite oxide is provided, which has a crystallite diameter of 6.5 nm or less and a BET specific surface area of 90 m.sup.2/g or more.

The present invention addresses to catalysts applicable to the conversion of CO to CO.sub.2 and H.sub.2 by the water-gas shift reaction. Such catalysts are made up of iron oxides, zirconium oxides, cerium oxides or a mixture of the same, promoted by platinum (Pt) contents between 0.1 and 0.4% m/m and with a sodium (Na) content below 0.01% m/m, based on the oxidized material. The present invention makes it possible to obtain catalysts with a high dispersion of Pt, with metallic particles of the order of 1 nm and methods of preparation by coprecipitation of soluble salts in aqueous medium using ammonium hydroxide as a precipitating agent.