# US 11,992,806 B2 · Four-way conversion catalyst having improved filter properties > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,992,806 B2 - Document ID: US11992806B2 - Status: Granted - Kind: B2 - Application number: 16/965,449 - Filed: 2019-02-04 - Published: 2020-11-12 - Granted: 2024-05-28 - Earliest claimed: 2018-02-05 - Assignees: BASF SE - Applicants: BASF Corporation - Inventors: Florian Waltz; Attilio Siani; Thomas Schmitz; Stephan Siemund; David Schlereth; Hao Li - Web page: https://patentgrep.com/patent/US11992806B2 ## CPC - B01D 53/945: {characterised by a specific catalyst} - B01J 23/63: with rare earths or actinides - F01N 3/022: characterised by specially adapted filtering structure, e.g. honeycomb, mesh or fibrous - F01N 3/0222: {the structure being monolithic, e.g. honeycombs} - F01N 3/035: with catalytic reactors - F01N 3/101: {Three-way catalysts} - B01D 2255/102: Platinum group metals - B01D 2255/1023: Palladium - B01D 2255/1025: Rhodium - B01D 2255/2042: Barium - B01D 2255/206: Rare earth metals - B01D 2255/20715: Zirconium - B01D 2255/407: Zr-Ce mixed oxides - B01D 2255/9155: Wall flow filters - F01N 2330/06: Ceramic, e.g. monoliths - 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 four-way conversion catalyst for the treatment of an exhaust gas stream of a gasoline engine, the catalyst comprising a porous wall flow filter substrate comprising an inlet end, an outlet end, a substrate axial length extending between the inlet end and the outlet end, and a plurality of passages defined by porous internal walls of the porous wall flow filter substrate, wherein the plurality of passages comprise inlet passages having an open inlet end and a closed outlet end, and outlet passages having a closed inlet end and an open outlet end; wherein in the pores of the porous internal walls and on the surface of the porous internal walls, which surface defines the interface between the porous internal walls and the passages, the catalyst comprises a three-way conversion catalytic coating comprising an oxygen storage compound and a platinum group metal supported on a refractory metal oxide; wherein in the pores of the porous internal walls, the three-way conversion catalytic coating is present as in-wall-coating and on the surface of the porous internal walls, the three-way conversion catalytic coating is present as on-wall-coating; wherein in addition to said three-way conversion catalytic coating, the catalyst comprises no further coating in the pores of the porous internal walls and no further coating on the surface of the porous internal walls. ## Claims ### Claim 1 A four-way conversion catalyst for the treatment of an exhaust gas stream of a gasoline engine, the catalyst comprising: a porous wall-flow filter substrate comprising an inlet end, an outlet end, a substrate axial length extending between the inlet end and the outlet end, and a plurality of passages defined by porous internal walls of the porous wall-flow filter substrate, wherein the plurality of passages comprise inlet passages having an open inlet end and a closed outlet end, and outlet passages having a closed inlet end and an open outlet end; wherein the surface of the porous internal walls defines the interface between the porous internal walls and the passages, and a three-way conversion catalytic coating comprising a platinum group metal supported on an oxygen storage compound, a platinum group metal supported on a refractory metal oxide support, and further comprising a promoter, wherein the promoter comprises zirconium and barium; wherein in the pores of the porous internal walls, the three-way conversion catalytic coating is present as an in-wall coating; wherein on the surface of the porous internal walls, the three-way conversion catalytic coating is present as an on-wall coating; and wherein in addition to the three-way conversion catalytic coating, the catalyst comprises no further coating in the pores of the porous internal walls and no further coating on the surface of the porous internal walls; wherein the four-way conversion catalyst is prepared by a process comprising (i) providing the porous wall-flow filter substrate, wherein the internal walls have an average pore size in the range of from 9 to 22 micrometers, and wherein the average porosity of the internal walls of the internal walls is in the range of from 20 to 75%; (ii) providing a washcoat slurry comprising particles of a source of the three-way conversion catalytic coating, said particles having a volume based particle size distribution Dv90 in the range of from 11 to 21 micrometers, comprising (ii.1) impregnating a source of a platinum group metal onto a refractory metal oxide support; admixing the platinum group metal supported on the refractory metal oxide with one or more of an adjuvant and a source of a promoter, obtaining a slurry comprising particles of a source of the three-way conversion catalytic coating, said particles having a volume based particle size distribution Dv90 of more than 21 micrometers; and milling said slurry obtaining a slurry wherein the particles comprised in said slurry have a volume based particle size distribution Dv90 in the range of from 11 to 21 micrometers; wherein milling said slurry comprises milling from 40 to 60 weight-% of said slurry obtaining a first slurry wherein the particles comprised in the first slurry have a volume based particle size distribution Dv90 in the range of from 16 to 21 micrometers and milling the remaining portion of said slurry obtaining a second slurry wherein the particles comprised in the second slurry have a volume based particle size distribution Dv90 in the range of from 4 to 8 micrometers, and combining said first slurry and said second slurry; (ii.2) impregnating a source of a platinum group metal onto an oxygen storage compound; admixing the platinum group metal supported on the oxygen storage compound with one or more of an adjuvant and a source of a promoter, obtaining a slurry comprising particles of a source of the three-way conversion catalytic, said particles having a volume based particle size distribution Dv90 in the range of from 11 to 21 micrometers; and milling said slurry obtaining a slurry wherein the particles comprised in said slurry have a volume based particle size distribution Dv90 in the range of from 11 to 21 micrometers; (ii.3) admixing the slurry obtained from (ii.1) and the slurry obtained from (ii.2), obtaining the washcoat slurry comprising a source of the three-way conversion catalytic coating; (iii) coating the porous internal walls of the porous wall-flow filter substrate provided in (i) with the particles of the washcoat slurry provided in (ii). ### Claim 2 (depends on 1) The four-way conversion catalyst of claim 1, comprising the three-way conversion catalytic coating at a total loading, l(total), in the range of from 0.1 to 5 wherein the total loading is the sum of l(in-wall coating) and l(on-wall coating), wherein l(in-wall coating) is the loading of the in-wall coating, and wherein l(on-wall coating) is the loading of the on-wall coating. ### Claim 3 (depends on 2) The four-way conversion catalyst of claim 2, having a loading ratio of l(on-wall coating): l(in-wall coating) in the range of from 1:99 to 50:50. ### Claim 4 (depends on 1) The four-way conversion catalyst of claim 1, wherein from 95 to 100 weight % of the four-way conversion catalyst consists of the porous wall-flow filter substrate and the three-way conversion catalytic coating. ### Claim 5 (depends on 4) The four-way conversion catalyst of claim 4, which consists of the porous wall-flow filter substrate and the three-way conversion catalytic coating. ### Claim 6 (depends on 1) The four-way conversion catalyst of claim 1, wherein the porous internal walls comprising the in-wall coating have a relative average porosity in the range of from 20 to 99%, and wherein the relative average porosity is defined as the average porosity of the internal walls comprising the in-wall coating. ### Claim 7 (depends on 1) The four-way conversion catalyst of claim 1, wherein the porous internal walls comprising the in-wall coating have a relative average pore size in the range of from 10 to 21 micrometer, and wherein the relative average pore size is defined as the average pore size of the internal walls comprising the in-wall coating relative to the average pore size of the internal walls not comprising the in-wall coating. ### Claim 8 (depends on 7) The four-way conversion catalyst of claim 7, wherein the average pore size of the internal walls not comprising the in-wall coating is in the range of from 9.5 to 21.5 micrometer. ### Claim 9 (depends on 1) The four-way conversion catalyst of claim 1, wherein the wall flow filter substrate comprises the three-way conversion catalytic coating at an inlet coating length of x % of the substrate axial length, wherein 00. ### Claim 10 (depends on 9) The four-way conversion catalyst of claim 9, wherein 0