US 11,053,833 B2
Exhaust gas purification catalyst
Isao Chinzei, Toyota (JP); Masahide Miura, Toyota (JP); Seiji Nakahigashi, Toyota (JP); Hiromasa Suzuki, Toyota (JP); Toshio Yamamoto, Nagakute (JP); Akira Morikawa, Nagakute (JP); Satoru Katoh, Nagakute (JP); Takashi Onozuka, Kakegawa (JP); Hirotaka Ori, Kakegawa (JP); Mitsuyoshi Okada, Kakegawa (JP); and Sho Hoshino, Kakegawa (JP)
Assigned to Toyota Jidosha Kabushiki Kaisha, Toyota (JP)
Filed by Isao Chinzei, Toyota (JP); Masahide Miura, Toyota (JP); Seiji Nakahigashi, Toyota (JP); Hiromasa Suzuki, Toyota (JP); Toshio Yamamoto, Nagakute (JP); Akira Morikawa, Nagakute (JP); Satoru Katoh, Nagakute (JP); Takashi Onozuka, Kakegawa (JP); Hirotaka Ori, Kakegawa (JP); Mitsuyoshi Okada, Kakegawa (JP); and Sho Hoshino, Kakegawa (JP)
Filed on Apr. 24, 2020, as Appl. No. 16/857,566.
Claims priority of application No. JP2019-088769 (JP), filed on May 9, 2019.
Prior Publication US 2020/0355106 A1, Nov. 12, 2020
Int. Cl. F01N 3/28 (2006.01); B01J 35/04 (2006.01)
CPC F01N 3/2803 (2013.01) [B01J 35/04 (2013.01); F01N 2370/02 (2013.01); F01N 2510/068 (2013.01)] 8 Claims
 
1. An exhaust gas purification catalyst comprising a catalyst coating layer on a substrate, the catalyst coating layer containing a noble metal and a metal oxide,
wherein in the catalyst coating layer:
an average thickness of the coating layer is in a range from 50 μm to 100 μm;
a porosity measured by a weight-in-water method is in a range from 50% by volume to 80% by volume; and
high-aspect-ratio pores having an aspect ratio of 5 or more account for 0.5% by volume to 50% by volume of a whole volume of voids, the high-aspect-ratio pore having an equivalent circle diameter in a range from 2 μm to 50 μm in a cross-sectional image of a catalyst coating layer cross section perpendicular to an exhaust gas flow direction of the substrate and having an average aspect ratio in a range from 10 to 50, and
wherein when a surface side in contact with an exhaust gas in a thickness direction of the catalyst coating layer is defined as 0% of thickness and a side in contact with the substrate is defined as 100% of thickness, 80% or more of a total amount by mass of the noble metal is present in a range from 25% of thickness or more and 70% of thickness or less.