An exhaust gas purification catalyst, characterized by having a catalyst layer containing palladium, rhodium, and alumina, which supports a sulfate of an alkaline-earth metal selected from barium sulfate and strontium sulfate, and the correlation coefficients .sub.Pd,AE and .sub.Rh,AE calculated from the characteristic X-ray intensity measured using an electron beam micro-analyzer for the palladium, rhodium, and alkaline-earth metal being +0.75 to +1.00 and 0.00 to +0.25, respectively, using 350 points as measurement points obtained by equally dividing the catalyst layer into 351 parts in the thickness direction on a virtual straight line that runs through the catalyst layer in the thickness direction.

The invention relates to a method for producing mesoporous metal carbide layer with defined nano-structuring, wherein during a first method step a mesoporous metal oxide layer is made available and in a second step, the metal oxide layer is brought in contact in a reducing atmosphere with a carbon source in the atmosphere, wherein the temperature is at least 650? C. and the heat-up rate ranges from 0.5 to 2 kelvin per minute.

The invention provides a process for preparing a cobalt-containing catalyst precursor. The process includes calcining a loaded catalyst support comprising a silica (SiO.sub.2) catalyst support supporting cobalt nitrate to convert the cobalt nitrate into cobalt oxide. The calcination includes heating the loaded catalyst support at a high heating rate, which does not fall below 10? C./minute, during at least a temperature range A. The temperature range A is from the lowest temperature at which calcination of the loaded catalyst support begins to 165? C. Gas flow is effected over the loaded catalyst support during at least the temperature range A. The catalyst precursor is reduced to obtain a Fischer-Tropsch catalyst.

An exhaust gas purification catalyst comprises a substrate and a catalyst layer on the substrate, and has a first section upstream along a flow direction of the exhaust gas and a second section downstream from the first section. The catalyst layer in the first section comprises a first catalyst layer comprising palladium and a second catalyst layer comprising rhodium and covering the first catalyst layer. A pore volume proportion, which is a proportion of a total volume of the pores having a pore diameter of 0.06-30.0 ?m as measured by mercury press-in method and existing in the substrate and the catalyst layer in the first section to a volume of a entire first section, is 12-18%. A wash coat amount, which is a mass per unit volume of the catalyst layer in the first section to the volume of the substrate existing in the first section, is 100-190 g/L.

An exhaust-gas purifying catalyst includes a lower layer containing ceria-based oxide particles and an upper layer containing metal oxide particles and a precious metal supported on the metal oxide particles, wherein the exhaust-gas purifying catalyst is characterized in that the Rh content of the lower layer is equal to or less than 0.25 g/L, and also that the particle-size distribution of the ceria-based oxide particles in the lower layer, which is obtained by scanning electron microscopy, has a first peak in which the peak top thereof is in a region of 0.90-6.50 m and a second peak in which the peak top thereof is in a region of 9.50-34.0 m.

A method for producing a conjugated diene according to an aspect of the present invention comprises a step of contacting a raw material gas containing an alkane with a dehydrogenation catalyst to obtain a product gas containing at least one unsaturated hydrocarbon selected from the group consisting of an olefin and a conjugated diene. In the production method, the dehydrogenation catalyst is a catalyst having a supported metal containing a Group 14 metal element and Pt supported on a support containing Al and a Group 2 metal element; the dehydrogenation catalyst has pores (a) having a pore diameter of 7 nm or more and 32 nm or less; and a proportion of a pore volume of the pores (a) is 65% or more of the total pore volume of the dehydrogenation catalyst.

There are provided an easily producible catalyst particle-holding structure used for production of carbon nanotubes, and a method for producing the same. The method for producing the catalyst particle-holding structure of the present invention used for production of carbon nanotubes includes a step of forming a catalyst particle forming layer containing Si, Al, and Fe, and a step of performing a heat treatment on the catalyst particle forming layer in an atmosphere containing oxygen, to form catalyst particles containing Fe. The catalyst particles are held by the catalyst particle forming layer so that the catalyst particles are partially embedded in the catalyst particle forming layer. The size and the number of the catalyst particles containing Fe are controlled by adjusting the amount of oxygen contained in the atmosphere for the heat treatment. Thus, the catalyst particle-holding structure is formed easily.

This invention provides a carrier for a synthesis gas production catalyst that can suppress carbon depositions and allows to efficiently produce synthesis gas on a stable basis for a long duration of time when producing synthesis gas by carbon dioxide reforming. It is a carrier to be used for producing synthesis gas containing carbon monoxide and hydrogen from source gas containing methane-containing light hydrocarbons and carbon dioxide. The carrier contains magnesium oxide grains and calcium oxide existing on the surfaces of magnesium oxide grains. The calcium oxide content thereof is between 0.005 mass % and 1.5 mass % in terms of Ca.

To provide a method for producing a hydrofluoroolefin, wherein formation of an over-reduced product having hydrogen added to an aimed hydrofluorolefin and an over-reduced product having some of fluorine atoms in the aimed product replaced with hydrogen atoms, as by-products, is suppressed. A method for producing a hydrofluoroolefin, which comprises reacting a specific chlorofluoroolefin with hydrogen in the presence of a catalyst supported on a carrier, to obtain a specific hydrofluoroolefin, wherein the catalyst is a catalyst composed of particles of an alloy containing at least one platinum group metal selected from the group consisting of palladium and platinum, and gold, and the proportion of the gold at the surface of the alloy particles is from 5 to 30 mass % per 100 mass % in total of the platinum group metal and the gold at the surface of the alloy particles.

A hydropyrolysis catalyst and a process using that catalyst are described. The catalyst comprises a support and an active metal component wherein the catalyst is an eggshell type catalyst having the active metal component located in the outer portion of the support.