A composite oxide catalyst includes Ce that is a first metal, La that is a second metal, and a third metal as contained metals. The third metal is a transition metal, or a rare-earth metal other than Ce and La. A Ce content in the contained metals is higher than or equal to 5 mol % and lower than or equal to 95 mol %. An La content in the contained metals is higher than or equal to 2 mol % and lower than or equal to 93 mol %. A content of the third metal in the contained metals is higher than or equal to 2 mol % and lower than or equal to 93 mol %.

An electrode catalyst for a fuel cell, the electrode catalyst having high initial activity and being capable of long-term retention of said activity; and a fuel cell using the electrode catalyst for a fuel cell. The electrode catalyst for a fuel cell includes catalyst metal particles that include platinum or a platinum alloy, and carrier particles that carry said catalyst metal particles, wherein the carrier particles are a carbonaceous material having a cumulative pore volume of 0.10 cc/g or less in the diameter range of 2 nm or less, and a BET specific surface area of greater than 900 m.sup.2/g; and a fuel cell comprising the electrode catalyst for a fuel cell.

Provided is a carbon dioxide reduction composite catalyst, comprising an organic-inorganic porous body, and a molecular reduction catalyst combined with the organic-inorganic porous body, wherein the organic-inorganic porous body includes metal oxide clusters, and a light-condensing organic material as linkers between the metal oxide clusters, and the linkers absorb visible light to form excitons, and move the excitons through energy transfer between the linkers to transfer the electrons of the excitons to the molecular reduction catalyst.

Disclosed are ceramic bodies comprised of composite cordierite aluminum magnesium titanate ceramic compositions and methods for the manufacture of same.

Provided herein is a novel process for providing a fixed catalyst bed including doped structured shaped catalyst bodies, to a reactor including such a fixed catalyst bed installed in a fixed location, and to a use of the fixed catalyst beds and reactors thus obtained for hydrogenation reactions.

The present invention relates to 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, wherein the honeycomb fired body is an extrudate containing ceria-zirconia composite oxide particles and alumina particles, and when the pore size of the partition wall of the honeycomb fired body is measured by mercury porosimetry, and the measurement results are shown as a pore size distribution curve with pore size (m) on the horizontal axis and log differential pore volume (ml) on the vertical axis, at least one peak is present in each of the pore size ranges of 0.01 to 0.1 m and 0.1 to 5 m.

Provided is a novel exhaust gas purification catalyst, which uses a Cu-based delafossite oxide, capable of increasing the exhaust gas purification performance compared to the case of using the Cu-based delafossite oxide alone. Proposed is an exhaust gas purification catalyst comprising a delafossite-type oxide represented by a general formula ABO.sub.2 and an inorganic porous material, wherein Cu is contained in the A site of the general formula of the delafossite oxide, one or two or more elements selected from the group consisting of Mn, Al, Cr, Ga, Fe, Co, Ni, In, La, Nd, Sm, Eu, Y, V, and Ti are contained in the B site thereof, and Cu is contained in 3 to 30% relative to the total content (mass) of the delafossite-type oxide and the inorganic porous material.

A layered-structure, multifunctional monolith catalyst is provided. The multifunctional monolith catalyst includes a monolithic substrate. A first layer is coated on a surface of the substrate. The first layer includes a first catalyst. A second layer is formed on top of the first layer. The second layer includes a second catalyst, and the second layer is porous. Layering of the first and second catalysts reduces degradation of one or both of the first and second catalysts, and increases a yield of the reaction catalyzed by the second catalyst. A method of converting carbon dioxide to dimethyl ether using the multifunctional monolith catalyst is also provided.

Provided is a method for manufacturing a catalyst with which it is possible to obtain a supported metal ammonia synthesis catalyst, in which there are restrictions in terms of producing method and producing facility, and particularly large restrictions for industrial-scale producing, in a more simple manner and so that the obtained catalyst has a high activity. This method for manufacturing an ammonia synthesis catalyst includes: a first step for preparing 12CaO.Math.7Al.sub.2O.sub.3 having a specific surface area of 5 m.sup.2/g or above; a second step for supporting a ruthenium compound on the 12CaO.Math.7Al.sub.2O.sub.3; and a third step for performing a reduction process on the 12CaO.Math.7Al.sub.2O.sub.3 supporting the ruthenium compound, obtained in the second step. This invention is characterized in that the reduction process is performed until the average particle diameter of the ruthenium after the reduction process has increased by at least 15% in relation to the average particle diameter of the ruthenium before the reduction process.

Provided is a catalyst precursor containing a Keggin-type heteropolyacid used for the production of an ,-unsaturated carboxylic acid by oxidation of an ,-unsaturated aldehyde.