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.

The present invention provides an exhaust gas purification catalyst including a base material and a catalyst layer 20 that is arranged on the base material. The catalyst layer 20 includes a catalyst metal and a carrying material carrying the catalyst metal. The catalyst layer 20 satisfies below: (1) in a pore distribution curve measured by a mercury porosimeter, a peak for the largest pore volume exists within a range of a pore diameter equal to or more than 1 μm and not more than 10 μm; and (2) on an electron microscopy observation image (with a 1000-fold magnification) of a surface of the catalyst layer 20, when areas of a plurality of voids comprised in the electron microscopy observation image are respectively calculated, a standard deviation for the areas of the plurality of voids is not more than 30 μm.sup.2.

The present invention relates to a mixed oxide of aluminium, of zirconium, of cerium, of lanthanum and optionally of at least one rare-earth metal other than cerium and lanthanum that makes it possible to prepare a catalyst that retains, after severe ageing, a good thermal stability and a good catalytic activity. The invention also relates to the process for preparing this mixed oxide and also to a process for treating exhaust gases from internal combustion engines using a catalyst prepared from this mixed oxide.

An automotive catalytic converter includes a three-way catalyst having Rh as the only precious metal configured as a front zone and a three-way catalyst having a mixture of Rh and Pd, Pt, or both configured as a rear zone, such that an exhaust gas from an internal combustion engine passes through the front zone before passing through the rear zone to minimize sulfur poisoning of the catalytic converter.

The present invention concerns a material with a non-stoichiometric spinel-type crystalline structure based on cobalt oxide doped with alkaline elements, its production process for obtaining it by precipitation with controlled washing, and its particular use as a highly active catalyst in the N.sub.2O decomposition reaction. Therefore, we understand that the present invention is in the area of green industry aimed at reducing N.sub.2O emissions into the atmosphere.

A honeycomb filter includes a honeycomb structure having a porous partition wall disposed to surround a plurality of cells; and a plugging portion provided at one end of the cell, wherein the honeycomb structure has an inflow side region including a range of up to at least 30% with respect to the total length of the honeycomb structure with the inflow end face as the starting point and an outflow side region including a range of up to at least 20% with respect to the total length of the honeycomb structure with the outflow end face as the starting point, in the extending direction of the cell of the honeycomb structure, an average pore diameter of the partition wall in the inflow side region is 9 to 14 μm and an average pore diameter of the partition wall in the outflow side region is 15 to 20 μm.

The technology herein disclosed provides a wall flow type exhaust gas purifying catalyst capable of establishing the compatibility between the noxious gas purifying performance and the pressure loss suppressing performance at a high level. The exhaust gas purifying catalyst herein disclosed includes a base material 11 and a catalyst layer 20. Then, a first catalyst region 22 including the catalyst layer 20 formed therein is provided on an entry side surface 16a of a partition wall 16 of the base material 11. A second catalyst region 24 including the catalyst layer 20 formed on a wall surface 18a of a pore 18 is provided in a prescribed region from an exit side surface 16b of the partition wall toward an entry side cell 12. Further, a catalyst unformed region 30 in which a catalyst layer is substantially not formed is provided between the first catalyst region 22 and the second catalyst region 24 in the thickness direction Y of the partition wall 16. As a result of this, it is possible to prevent the deposition of PMs in the second catalyst region 24 including the catalyst layer 20 formed in the pore 18, and to establish the compatibility between the noxious gas purifying performance and the pressure loss suppressing performance at a high level.

The present disclosure relates to a titanium-organic framework photocatalyst for adsorption and decomposition of a volatile organic compound, a method for preparing the same and a method for removing a volatile organic compound using a titanium-organic framework photocatalyst. More specifically, a hierarchical pore structure can be formed and a pore size can be controlled by preparing a titanium-organic framework photocatalyst by coordination bonding a titanium precursor to a mixture of two carboxylic acid compounds having different electronegativity, as organic linkers, at an optimized ratio. The titanium-organic framework photocatalyst exhibits improved efficiency of adsorbing and decomposing a volatile organic compound (VOC) and can improve the photocatalytic degradation rate of the volatile organic compound (VOC).

A catalytic composition is disclosed, which exhibits an X-ray amorphous oxide with a spinel formula, and crystals of ZnO, CuO, and at least one Group VIB metal oxide, and preferably, at least one acidic oxide of B, P. or Si, as well. The composition is useful in oxidative processes for removing sulfur from gaseous hydrocarbons.