Toyota Jidosha Kabushiki Kaisha

Cataler Corporation

Cataier Corporation

Tetsuhiro Hirao

Masahide Miura

Toshitaka Tanabe

Hirotaka Ori

Yoshinori Saito

Hiromasa Suzuki

Keiichi Narita

Tatsuya Ohashi

Satoru Katoh

Michihiko Takeuchi

Hiroaki Naito

Tadashi Suzuki

Ryota Onoe

Isao Chinzei

Masanao Sato

Kazunari Sawada

Miura Masahide

Saito Yoshinori

Suzuki Hiromasa

Toshitata Tanabe

An exhaust gas purification catalyst having a substrate having a wall flow structure, and a catalyst layer. The catalyst layer has: an A section provided in the interior of the partition wall, along an extension direction X of the partition wall, from an exhaust gas inflow end section; a C section provided in the interior of the partition wall, along the extension direction X of the partition wall, from an exhaust gas outflow end section; and a B section disposed between the A section and the C section in the extension direction X of the partition wall, and provided over the surface of the partition wall on the side in contact with the inlet cell, the interior of the partition wall, and the surface of the partition wall on the side in contact with the outlet cell.

Exhaust gas purification catalyst

An object of the present invention is to provide an exhaust gas purification catalyst which can exhibit sufficient purification performance even under a high Ga condition. The present invention relates to an exhaust gas purification catalyst comprising a substrate and a catalyst coating layer formed on the substrate, wherein the catalyst coating layer comprises catalyst particles, the catalyst coating layer having an upstream region extending by 40 to 60% of the entire length of the substrate from an upstream end of the catalyst in the direction of an exhaust gas flow and a downstream region corresponding to the remainder portion of the catalyst coating layer, the composition of the catalyst particle of the upstream region being different from that of the downstream region. The downstream region in the direction of an exhaust gas flow has a structure where a void is included in a large number, and furthermore high-aspect-ratio pores having an aspect ratio of 5 or more account for a certain percentage or more of the whole volume of voids. Thus, the exhaust gas purification catalyst exhibits enhanced purification performance.

The problem of the present invention is to provide an exhaust gas purification catalyst which can exhibit sufficient purification performance under a high Ga condition while having a resistance to stress such as high-temperature and poisonous substances. The present invention relates to an exhaust gas purification catalyst comprising two or more catalyst coating layers on a substrate, wherein a lower catalyst coating layer that is present lower with respect to an uppermost catalyst coating layer has a structure where a large number of voids are included and high-aspect-ratio pores having an aspect ratio of 5 or more account for a certain proportion or more of the whole volume of voids, thereby to improve gas diffusivity in the lower catalyst coating layer.

An object of the present invention is to provide an exhaust gas purification catalyst which can exhibit high durability and warm-up performance. The present invention relates to an exhaust gas purification catalyst comprising a substrate and a catalyst coating layer formed on the substrate, wherein the catalyst coating layer comprises catalyst particles, the catalyst coating layer having an upstream region extending by 40 to 60% of the entire length of the substrate from an upstream end of the catalyst in the direction of an exhaust gas flow and a downstream region corresponding to the remainder portion of the catalyst coating layer, the composition of the catalyst particle of the upstream region being different from that of the downstream region. The upstream region in the direction of an exhaust gas flow has a structure where a void is included in a large number, and furthermore high-aspect-ratio pores having an aspect ratio of 5 or more account for a certain percentage or more of the whole volume of voids. Thus, the exhaust gas purification catalyst exhibits enhanced purification performance.

When the amount of coating is increased in a two-layer catalyst or the like containing two noble metals in respective different layers, gas diffusivity in the catalyst and use efficiency of a catalytic active site are reduced to thereby reduce purification performance. In view of this, an organic fiber having a predetermined shape is used as a pore-forming material in formation of an uppermost catalyst coating layer of a multi-layer catalyst, to thereby form an uppermost catalyst coating layer having a high-aspect-ratio pore excellent in connectivity and therefore excellent gas diffusivity.

The present invention is directed to address the following problem: in an exhaust gas purification catalyst comprising a dual catalyst of a combination of a startup catalyst and an underfloor catalyst, reduction in the gas diffusivity of the underfloor catalyst results in reduction in the use efficiency of a catalytic active site, resulting in reduction in purification performance. The present invention relates to an exhaust gas purification catalyst comprising a dual catalyst of a combination of a startup catalyst and an underfloor catalyst having a catalyst coating where a large number of voids are included, wherein high-aspect-ratio pores having an aspect ratio of 5 or more account for a certain rate or more of the whole volume of the voids, to thereby enhance the purification performance of the catalyst.

An exhaust gas purification catalyst having a base and a catalytic coating layer formed thereon includes an alumina support, a platinum-group metal, an iron oxide-zirconia-based composite oxide, and a lanthanoid oxide in the same catalytic coating layer.

Exhaust gas purification catalyst for motor vehicle

A catalyst for exhaust gas purification is described which includes a substrate and a catalyst coating layer provided on the substrate. The catalyst coating layer includes first and second metal oxide particles. The first metal oxide particles have a catalyst metal supported thereon, and the second metal oxide particles do not have a catalyst metal supported thereon. The first and second metal oxide particles have a specific particle size. This is because, when the sizes of the particles supporting the catalyst metal remain relatively large but the sizes of the particles not supporting a catalyst metal are minimized, it is possible to decrease the thickness of the catalyst coating layer while maintaining durability and improving gas diffusibility of the coating layer. Therefore, a thickness of the catalyst coating is decreased without decreasing durability, and the catalyst can exhibit high exhaust gas purification performance even under high load conditions.

Catalyst for exhaust gas purification

Provided is an exhaust gas control catalyst including: a substrate (); and a catalyst layer () that is arranged on the substrate, in which the catalyst layer () includes a palladium region () that contains palladium, aluminum oxide, ceria-zirconia solid solution, and a composite oxide of lanthanum, iron, and zirconium, and a rhodium region () that is arranged adjacent to the palladium region along a plane direction of the catalyst layer and contains rhodium, aluminum oxide, and ceria-zirconia solid solution.

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Toyota, Japan

Tetsuhiro Hirao