# US 2010/0166629 A1 · Oxidation Catalyst With Low CO and HC Light-Off and Systems and Methods > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2010/0166629 A1 - Document ID: US20100166629A1 - Status: Published application - Kind: A1 - Application number: 12/643,614 - Filed: 2009-12-21 - Published: 2010-07-01 - Earliest claimed: 2008-12-29 - Assignees: BASF Catalysts LLC - Inventors: Michel Deeba - Web page: https://patentgrep.com/patent/US20100166629A1 ## CPC - B01D 53/944: {Simultaneously removing carbon monoxide, hydrocarbons or carbon making use of oxidation catalysts (three-way-catalysts [TWC] B01D53/9445)} - B01J 21/066: {Zirconium or hafnium; Oxides or hydroxides thereof} - B01J 23/63: with rare earths or actinides - B01J 29/7007: {Zeolite Beta} - B01J 35/40: characterised by dimensions, e.g. grain size (in a colloidal state B01J35/23; crystallite size B01J35/77) - B01J 35/57: Honeycombs - B01J 37/0244: {Coatings comprising several layers} - B01J 37/0246: {Coatings comprising a zeolite} - B01J 37/0248: {Coatings comprising impregnated particles} - B01J 37/10: in the presence of water, e.g. steam - B01D 2255/1021: Platinum - B01D 2255/1023: Palladium - B01D 2255/206: Rare earth metals - B01D 2255/407: Zr-Ce mixed oxides - B01D 2255/502: Beta zeolites - B01D 2255/9022: Two layers - B01D 2255/9025: Three layers - B01D 2255/912: HC-storage component incorporated in the catalyst - B01D 2258/012: Diesel engines and lean burn gasoline engines - B01J 29/082: {X-type faujasite} - B01J 29/084: {Y-type faujasite} - B01J 29/40: of the pentasil type, e.g. types ZSM-5, ZSM-8 or ZSM-11, as exemplified by patent documents US3702886, GB1334243 and US3709979, respectively - B01J 29/85: Silicoaluminophosphates [SAPO compounds] - B01J 29/89: Silicates, aluminosilicates or borosilicates of titanium, zirconium or hafnium {(B01J29/005 takes precedence)} - Y02A 50/20: Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters - 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 - Y02A: TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE ## Abstract An oxidation catalyst for the treatment of exhaust gas emissions, such as the oxidation of unburned hydrocarbons (HC), and carbon monoxide (CO) and the reduction of nitrogen oxides (NOx) from a diesel engine and methods of exhaust gas treatment are disclosed. More particularly, a washcoat composition is disclosed comprising at least two washcoat layers, a first washcoat comprising palladium supported on ceria-zirconia and ceria-zirconia-alumina and a second washcoat containing one or more of platinum and palladium and one or more hydrocarbon storage components. An undercoat may also be included in the catalyst. Also disclosed are method of exhaust gas treatment and diesel exhaust gas treatment systems that include the oxidation catalyst and a downstream soot filter. ## Claims ### Claim 1 An oxidation catalyst for abatement of exhaust gas emissions from an engine comprising: a carrier substrate; an undercoat coated on the carrier substrate, the undercoat comprising a refractory metal oxide support; and a first washcoat layer comprising a support material selected from ceria-zirconia and ceria-zirconia-alumina and a precious metal catalyst containing palladium (Pd), wherein said first washcoat layer does not contain a zeolite. ### Claim 2 (depends on 1) The oxidation catalyst of claim 1, wherein the refractory metal oxide comprises alumina, ceria, zirconia, ceria-alumina, ceria-zirconia, ceria-zirconia-alumina, and mixtures thereof. ### Claim 3 (depends on 2) The oxidation catalyst of claim 2, wherein the refractory metal oxide further comprises one or more promoters selected from oxides of lanthanum, yttrium, neodymium, praseodymium, samarium, and strontium. ### Claim 4 (depends on 1) The oxidation catalyst of claim 1, wherein the undercoat further comprises a hydrocarbon storage component comprising a molecular sieve. ### Claim 5 (depends on 4) The oxidation catalyst of claim 4, wherein the molecular sieve is selected from a beta zeolite, a molecular sieve having a CHA structure, X zeolite, Y zeolite, silicoaluminophosphates, and pentasil. ### Claim 6 (depends on 1) The oxidation catalyst of claim 1, wherein the first washcoat layer contains substantially no platinum. ### Claim 7 (depends on 1) The oxidation catalyst of claim 1, further comprising a second washcoat layer coated over said first washcoat layer comprising a support material and a precious metal catalyst containing one or more of platinum (Pt) and palladium (Pd), and at least one of the undercoat or the second washcoat layer comprises one or more hydrocarbon storage components. ### Claim 8 (depends on 7) The oxidation catalyst of claim 7, wherein the undercoat comprises a hydrocarbon storage component comprising a molecular sieve. ### Claim 9 (depends on 8) The oxidation catalyst of claim 8, wherein the molecular sieve is selected from faujasite, chabazite, clinoptilolite, mordenite, silicalite, zeolite X, zeolite Y, ultrastable zeolite Y, ZSM zeolite, offretite, and beta zeolite. ### Claim 10 (depends on 8) The oxidation catalyst of claim 8, wherein the molecular sieve comprises beta zeolite. ### Claim 11 (depends on 7) The oxidation catalyst of claim 7, wherein said second washcoat layer contains platinum and palladium in a Pt:Pd ratio in the range of about 1:1 to 10:1. ### Claim 12 (depends on 7) The oxidation catalyst of claim 7, wherein said second washcoat layer contains platinum and palladium in a Pt:Pd ratio in the range of about 1:1 to 2:1. ### Claim 13 (depends on 7) The oxidation catalyst of claim 7, wherein the first washcoat layer is substantially silica free. ### Claim 14 (depends on 7) The oxidation catalyst of claim 7, wherein one or more of the undercoat and second washcoat layer further comprises a ceria-zirconia material. ### Claim 15 (depends on 7) The oxidation catalyst of claim 7, wherein the second washcoat layer comprises a molecular sieve. ### Claim 16 (depends on 15) The oxidation catalyst of claim 15, wherein the molecular sieve comprises beta zeolite. ### Claim 17 (depends on 13) The oxidation catalyst of claim 13, wherein the second washcoat layer comprises one or more of alumina and silica-alumina. ### Claim 18 (depends on 1) The oxidation catalyst of claim 1, wherein the substrate comprises a honeycomb substrate comprising substantially parallel gas flow passages extending from an inlet or an outlet face of the substrate defined by walls on which the washcoat layers are coated so that gases flowing through the passages contact material contained in the layers. ### Claim 19 (depends on 7) The oxidation catalyst of claim 7, wherein the substrate comprises a honeycomb substrate comprising substantially parallel gas flow passages extending from an inlet or an outlet face of the substrate defined by walls on which the washcoat layers are coated so that gases flowing through the passages contact material contained in the layers. ### Claim 20 A method for treating a diesel exhaust gas stream comprising: contacting the exhaust gas stream with a top layer catalyst coated over a first catalyst layer, the top layer catalyst comprising a support material, one or more hydrocarbon storage components, and a precious metal catalyst containing one or more of platinum (Pt) and palladium (Pd); and after contacting the exhaust gas stream with the top layer catalyst, contacting the exhaust gas stream with a first catalyst layer comprising a support material selected from ceria-zirconia and ceria-zirconia-alumina and a precious metal catalyst containing palladium (Pd) and substantially no platinum, wherein said first catalyst layer does not contain a zeolite. ### Claim 21 (depends on 20) The method of claim 20, wherein the hydrocarbon storage component comprises a zeolite. ### Claim 22 (depends on 21) The method of claim 21, wherein the zeolite is selected from faujasite, chabazite, clinoptilolite, mordenite, silicalite, zeolite X, zeolite Y, ultrastable zeolite Y, ZSM zeolite, offretite, and beta zeolite. ### Claim 23 (depends on 22) The method of claim 22, wherein the zeolite comprises beta zeolite. ### Claim 24 (depends on 23) The method of claim 23, wherein the top washcoat layer contains platinum and palladium in a Pt:Pd ratio in the range of about 1:1 to 2:1. ### Claim 25 (depends on 24) The method of claim 24, wherein said diesel exhaust gas stream subsequent to contacting said oxidation catalyst is directed to a catalyzed soot filter (CSF) located downstream of said diesel oxidation catalyst. ### Claim 26 (depends on 25) The method of claim 25, wherein said diesel exhaust gas stream subsequent to contacting said catalyzed soot filter (CSF) is directed to a selective catalytic reduction (SCR) component located downstream of said catalyzed soot filter (CSF).