Porous alumina having excellent heat resistance and coking resistance is provided. The porous alumina can include silica and barium oxide added to aluminum oxide, wherein a ratio of SiO2 addition amount to a total mass of aluminum oxide and SiO2 addition amount is defined as SiO2 addition ratio (mass %), a ratio of BaO addition amount to a total mass of aluminum oxide and SiO2 addition amount is defined as BaO addition ratio (mass %), when the SiO2 addition ratio is within a range of 3 mass % or less and the BaO addition ratio is within a range of 14 mass % or less, the silica and the barium oxide are respectively added to the aluminum oxide so that a specific surface area of the porous alumina measured by a measuring method after heat treatment is equal to or larger than a reference specific surface area of reference porous alumina.

A supported catalyst for decomposing an organic substance that includes a support and a catalyst particle supported on the support. The catalyst particle contains a perovskite-type composite oxide represented by A.sub.xB.sub.yM.sub.zO.sub.w, where the A contains at least one selected from Ba and Sr, the B contains Zr, the M is at least one selected from Mn, Co, Ni and Fe, y+z=1, x≥0.995, z≤0.4, and w is a positive value satisfying electrical neutrality. A film thickness of a catalyst-supporting film supported on the support and containing the catalyst particle is 5 μm or more, or a supported amount as determined by normalizing a mass of the catalyst particle supported on the support by a volume of the support is 45 g/L or more.

A supported catalyst for decomposing an organic substance that includes a support and a catalyst particle supported on the support. The catalyst particle contains a perovskite-type composite oxide represented by A.sub.xB.sub.yM.sub.zO.sub.w, where the A contains at least one selected from Ba and Sr, the B contains Zr, the M is at least one selected from Mn, Co, Ni and Fe, y+z=1, x≥0.995, z≤0.4, and w is a positive value satisfying electrical neutrality. A film thickness of a catalyst-supporting film supported on the support and containing the catalyst particle is 5 μm or more, or a supported amount as determined by normalizing a mass of the catalyst particle supported on the support by a volume of the support is 45 g/L or more.

Catalysts, catalytic materials having catalysts present on supports and catalytic methods are provided. The catalysts, catalytic material and methods are useful in a variety of catalytic reactions, for example, the oxidative coupling of methane.

Catalysts, catalytic materials having catalysts present on supports and catalytic methods are provided. The catalysts, catalytic material and methods are useful in a variety of catalytic reactions, for example, the oxidative coupling of methane.

A catalyst composition comprising MgO, Al.sub.2O.sub.3 and one or more further alkaline earth metal oxides, provides for outstanding catalytic production of propylene when employed together with a metathesis catalyst.

A catalyst composition comprising MgO, Al.sub.2O.sub.3 and one or more further alkaline earth metal oxides, provides for outstanding catalytic production of propylene when employed together with a metathesis catalyst.

A NO.sub.x adsorber catalyst and its use in an emission treatment system for internal combustion engines, is disclosed. The NO.sub.x adsorber catalyst comprises a first layer consisting essentially of a support material, one or more platinum group metals disposed on the support material, and a NO.sub.x storage material.

A NO.sub.x adsorber catalyst and its use in an emission treatment system for internal combustion engines, is disclosed. The NO.sub.x adsorber catalyst comprises a first layer consisting essentially of a support material, one or more platinum group metals disposed on the support material, and a NO.sub.x storage material.

The object of the present invention is to provide an exhaust gas purifying catalyst that can achieve high purification performance while suppressing H.sub.2S emissions. The object is solved by an exhaust gas purifying catalyst in which the top layer of a catalyst coating layer comprises a ceria-zirconia composite oxide having a pyrochlore-type ordered array structure, in which the ceria-zirconia composite oxide contains at least one additional element selected from the group consisting of praseodymium, lanthanum, and yttrium at 0.5 to 5.0 mol % in relation to the total cation amount, and the molar ratio of (cerium+additional element):(zirconium) is within the range from 43:57 to 48:52.