US 11,795,855 B2
Exhaust gas purification catalyst
Isao Chinzei, Toyota (JP); Takahiro Nishio, Toyota (JP); Shogo Shirakawa, Toyota (JP); Masahide Miura, Toyota (JP); Hiromasa Suzuki, Toyota (JP); Yuki Kido, Kakegawa (JP); Minoru Ito, Kakegawa (JP); Sho Hoshino, Kakegawa (JP); and Shin Nakayama, Kakegawa (JP)
Assigned to TOYOTA JIDOSHA KABUSHIKI KAISHA, Toyota (JP); and CATALER CORPORATION, Kakegawa (JP)
Filed by Isao Chinzei, Toyota (JP); Takahiro Nishio, Toyota (JP); Shogo Shirakawa, Toyota (JP); Masahide Miura, Toyota (JP); Hiromasa Suzuki, Toyota (JP); Yuki Kido, Kakegawa (JP); Minoru Ito, Kakegawa (JP); Sho Hoshino, Kakegawa (JP); and Shin Nakayama, Kakegawa (JP)
Filed on Mar. 24, 2021, as Appl. No. 17/211,112.
Claims priority of application No. JP2020-054639 (JP), filed on Mar. 25, 2020.
Prior Publication US 2021/0301706 A1, Sep. 30, 2021
Int. Cl. F01N 3/28 (2006.01); B01J 23/44 (2006.01); B01J 23/46 (2006.01); B01J 21/14 (2006.01); B01J 35/00 (2006.01); B01J 35/02 (2006.01)
CPC F01N 3/2803 (2013.01) [B01J 21/14 (2013.01); B01J 23/44 (2013.01); B01J 23/464 (2013.01); B01J 35/0006 (2013.01); B01J 35/023 (2013.01); F01N 2370/02 (2013.01); F01N 2510/0684 (2013.01)] 2 Claims
 
1. An exhaust gas purification catalyst comprising:
a substrate; and
a catalyst coating layer formed on the substrate,
wherein the catalyst coating layer comprises at least a first catalyst coating layer, a second catalyst coating layer, and a third catalyst coating layer, the first catalyst coating layer is formed on the substrate, the second catalyst coating layer is formed on the first catalyst coating layer, and the third catalyst coating layer is formed on the second catalyst coating layer,
wherein the first catalyst coating layer contains Pd as a catalyst metal, and is formed in a range of a length of 15% or more to 60% or less of an entire length of the substrate from an upstream end surface in an exhaust gas flow direction,
wherein the second catalyst coating layer contains Rh as a catalyst metal, and is formed in a range of a length of 60% or more to 100% or less of the entire length of the substrate from a downstream end surface in the exhaust gas flow direction,
wherein the third catalyst coating layer contains Pd as a catalyst metal, and is formed in a range of a length of 15% or more to 100% or less of the entire length of the substrate from the upstream end surface in the exhaust gas flow direction, and
wherein Rh in the second catalyst coating layer is Rh fine particles having an average particle size of 1.0 nm or more to 2.0 nm or less measured by a transmission electron microscope observation, and a standard deviation a of the particle size of 0.8 nm or less.