Catalyst for purifying the exhaust gases of diesel engines and process for the preparation thereof

• Main Authors: DOMESLE RAINER, KREUZER THOMAS, LOX EGBERT, KLEIN HARALD
• Format: Patent
• Language: English; Korean
• Published: 13.09.2001
• Edition: 7
• Subjects: BLASTING; CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOIDCHEMISTRY; ENGINE PLANTS IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNALCOMBUSTION ENGINES; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES ORENGINES IN GENERAL; HEATING; LIGHTING; MACHINES OR ENGINES IN GENERAL; MECHANICAL ENGINEERING; PERFORMING OPERATIONS; PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL; SEPARATION; STEAM ENGINES; THEIR RELEVANT APPARATUS; TRANSPORTING; WEAPONS

PURPOSE: Provided is a catalyst for purifying the exhaust gases of diesel engines, and process for the preparation thereof. CONSTITUTION: A catalyst for purifying the exhaust gases of a diesel engine, comprising a support material containing at least one zeolite and, additionally, at least one of the support oxides selected from the group consisting of aluminum oxide, silicon dioxide, titanium dioxide, zirconium dioxide and aluminum silicate and mixed oxides thereof and at least one of the noble metals selected from the group consisting of platinum, palladium, rhodium, iridium, gold and silver, wherein atoms of the noble metals present in catalyst have a mean oxidation number of less than +2.5, on average more than 3 metal ligands and less than 3 oxygen ligands and are present on the zeolite and support oxides in the form of crystallites having a mean particle size of from 1 to 6 nm. 본 발명은, 촉매가 하나 이상의 제올라이트 및 추가로 산화알루미늄, 이산화규소, 이산화티탄 및 규산알루미늄과 같은 캐리어 산화물중 하나 이상 및 플라티늄, 팔라듐, 로듐 및 이리듐과 같은 귀금속중 하나 이상을 포함하는, 디젤 엔진의 배기 가스를 정화하기 위한 촉매에 관한 것이다. 촉매는 귀금속의 원자가 +2.5이하의 평균 산화수를 갖고, 평균적으로 3개 이상의 금속 리간드 및 3개 이하의 산소 리간드를 가지며 평균 입자 크기가 1 내지 6nm인 미결정 형태로서 제올라이트 및 캐리어 산화물상에 존재함을 특징으로한다.