# US 2018/0021726 A1 · Exhaust gas purification catalyst > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2018/0021726 A1 - Document ID: US20180021726A1 - Status: Published application - Kind: A1 - Application number: 15/550,078 - Filed: 2016-02-16 - Published: 2018-01-25 - Earliest claimed: 2015-02-17 - Assignees: Cataler Corporation; Toyota Jidosha Kabushiki Kaisha - Applicants: Cataler Corporation; Toyota Jidosha Kabushiki Kaisha - Inventors: Ryota ONOE; Shingo SAKAGAMI; Yasutaka NOMURA; Yuta MORISHITA; Junji KURIYAMA; Hiroshi SEKINE; Daisuke OCHIAI; Naoto MIYOSHI; Masahiko TAKEUCHI; Akemi SATO - Web page: https://patentgrep.com/patent/US20180021726A1 ## CPC - B01D 53/945: {characterised by a specific catalyst} - B01D 53/94: by catalytic processes - B01J 23/63: with rare earths or actinides - B01J 35/19: {Catalysts containing parts with different compositions} - F01N 3/0222: {the structure being monolithic, e.g. honeycombs} - F01N 3/035: with catalytic reactors - F01N 3/0864: {Oxygen} - B01D 2255/1023: Palladium - B01D 2255/1025: Rhodium - B01D 2255/9022: Two layers - B01D 2255/908: O2-storage component incorporated in the catalyst - B01D 2255/9155: Wall flow filters - B01J 35/56: Foraminous structures having flow-through passages or channels, e.g. grids or three-dimensional [3D] monoliths - F01N 3/10: by thermal or catalytic conversion of noxious components of exhaust - F01N 3/281: {Metallic honeycomb monoliths made of stacked or rolled sheets, foils or plates} - F01N 2330/02: Metallic plates or honeycombs, e.g. superposed or rolled-up corrugated or otherwise deformed sheet metal - F01N 2510/0682: having a discontinuous, uneven or partially overlapping coating of catalytic material, e.g. higher amount of material upstream than downstream or vice versa - F01N 2510/0684: having more than one coating layer, e.g. multi-layered coatings - Y02T 10/12: Improving ICE efficiencies - B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28) - B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS - F01N: GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL-COMBUSTION ENGINES (arrangements in connection with gas exhaust of propulsion units in vehicles B60K13/00; combustion-air intake silencers specially adapted for, or arranged on, internal-combustion engines F02M35/00; protecting against, or damping, noise in general G10K11/16) - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract A wall-flow-type exhaust gas purification catalyst with an oxygen storage material that has an increased OSC and exhibits its OSC without a compromise provides an exhaust gas purification catalyst having a wall-flow-type substrate, a first catalytic layer and a second catalytic layer. The first catalytic layer is provided to an internal portion of a partition wall in contact with an entrance cell. The second catalytic layer is provided to an internal portion of a partition wall in contact with an exit cell. Each of the first and second catalytic layers has an oxygen storage material. The ratio (D1/D2) of the coating density D1 of the first catalytic layer to the coating density D2 of the second catalytic layer is 1.1 to 1.8. ## Claims ### Claim 1 A wall-flow-type exhaust gas purification catalyst to be placed in an exhaust pipe of an internal combustion system to purify exhaust gas emitted from the internal combustion system, the exhaust gas purification catalyst comprising: a substrate having a wall-flow structure with an exhaust inlet-side end and an exhaust outlet-side end, the substrate having an entrance cell that is open on the exhaust inlet-side end and an exit cell that is open on the exhaust outlet-side end, separated with a porous partition wall, a first catalytic layer provided to an internal portion of the partition wall in contact with the entrance cell, having a length L1 from the exhaust inlet-side end in the running direction of the partition wall with L1 being less than the total length Lw of the partition wall in the running direction, a second catalytic layer provided to an internal portion of the partition wall in contact with the exit cell, having a length L2 from the exhaust outlet-side end in the running direction of the partition wall with L2 being less than the total length Lw of the partition wall in the running direction; wherein in the internal portion of the partition wall in contact with the entrance cell, near the exhaust outlet-side end, the exhaust gas purification catalyst has a substrate-exposing segment free of the first and second catalytic layers, each of the first and second catalytic layers comprises an oxygen storage material, and the first catalytic layer has a coating density D1 and the second catalytic layer has a coating density D2 with a D1/D2 ratio value of 1.1 or higher, but 1.8 or lower. ### Claim 2 (depends on 1) The exhaust gas purification catalyst according to claim 1 wherein D1/D2 is 1.4 or higher, but 1.7 or lower. ### Claim 3 (depends on 1) The exhaust gas purification catalyst according to claim 1 having an overall average catalyst coating density DA of 40 g/L or greater, but 150 g/L or less. ### Claim 4 (depends on 1) The exhaust gas purification catalyst according to claim 1 wherein the first catalytic layer has an oxygen storage material content O1 per L of the substrate and the second catalytic layer has an oxygen storage material content O2 per L of the substrate, satisfying O1>O2. ### Claim 5 (depends on 4) The exhaust gas purification catalyst according to claim 4 having an O1 to O2 ratio (O1/O2) of 1.4 or higher, but 1.7 or lower. ### Claim 6 (depends on 4) The exhaust gas purification catalyst according to claim 4 wherein the oxygen storage material content O1 is 30 g/L or greater, but 50 g/L or less; and the oxygen storage material content O2 is 20 g/L or greater, but 35 g/L or less. ### Claim 7 (depends on 1) The exhaust gas purification catalyst according to claim 1 wherein each of the first catalytic layer and the second catalytic layer comprises the oxygen storage material as a promoter carrying no catalytic metal. ### Claim 8 (depends on 1) The exhaust gas purification catalyst according to claim 1 wherein the first catalytic layer comprises rhodium. ### Claim 9 (depends on 1) The exhaust gas purification catalyst according to claim 1 wherein the second catalytic layer comprises palladium. ### Claim 10 (depends on 1) The exhaust gas purification catalyst according to claim 1 wherein the first and second catalytic layers are formed to partially overlap each other in the running direction, with Lw, L1 and L2 satisfying the next inequality: Lw<(L1+L2)<2Lw. ### Claim 11 (depends on 1) The exhaust gas purification catalyst according to claim 1 wherein the partition wall has a total thickness Tw in a direction perpendicular to the running direction of the partition wall, the first catalytic layer has a thickness T1, the second catalytic layer has a thickness T2, and the first and second catalytic layers are formed to partially overlap each other in the thickness direction, with Tw, T1 and T2 satisfying the next inequality: Tw<(T1+T2)<2Tw.