摘要:
A catalyst for purification of exhaust gases, comprising a monolithic carrier and a catalyst layer formed thereon for reduction of the carbon monoxide, hydrocarbons and nitrogen oxides emitted from internal combustion engines, wherein (1) the catalyst layer contains catalyst particles each comprising a heat-resistant inorganic oxide and at least one noble metal selected from Pt, Pd and Rh, loaded thereon, (2) the catalyst layer contains, as a whole, three noble metals of Pt, Pd and Rh, (3) the catalyst layer contains, at any position ranging from the outer surface to the midpoint of the thickness, catalyst particles comprising a heat-resistant inorganic oxide and 2-10% by weight, based on the inorganic oxide, of Pd loaded thereon, and (4) the catalyst layer has, at the outer surface, exposed catalyst particles comprising an heat-resistant inorganic oxide and at least Rh loaded thereon.
摘要:
A reformer includes two or more catalyst units in the flow path, capable of generating hydrogen from a reactant fluid containing an organic compound or carbon monoxide, by catalysis. In the reformer, at least two of the catalyst units satisfy the following relationship: Heat capacity of the upstream-side catalyst unit≦Heat capacity of the downstream-side catalyst unit. The reformer is improved in the relationship between these catalyst units with respect to heat capacity. This improvement leads to improvement of the reformer in safety, heating characteristics during the start-up period, efficiency of hydrogen production and reduction in production of CO as the coproduct.
摘要:
A catalyst-adsorbent for purification of exhaust gases, including a monolithic carrier and a catalyst-adsorbent layer formed thereon, the catalyst-adsorbent layer including a catalyst for reduction of the carbon monoxide, hydrocarbons and nitrogen oxides emitted from internal combustion engines and an adsorbent for reduction of the hydrocarbons emitted during cold start of the engines. The catalyst is composed mainly of catalyst particles each including a heat-resistant inorganic oxide and at least one noble metal selected from Pt, Pd and Rh, loaded thereon, the catalyst containing at least catalyst particles each comprising a heat-resistant inorganic oxide and 2-30% by weight, based on the oxide, of Pd loaded thereon, the adsorbent comprising adsorbent particles composed mainly of zeolite.
摘要:
A catalyst for exhaust gas purification has at least one monolith carrier, at least one first catalyst layer having a three-way catalytic activity, provided on the carrier, and a second catalyst layer having a hydrocarbon purification activity, provided on the first catalyst layer. In a gasoline engine automobile provided with the above catalyst for exhaust gas purification in the exhaust gas system, the hydrocarbons present in the exhaust gas can be converted at a high efficiency by introducing secondary air into the exhaust gas in front of the catalyst to make the exhaust gas lean, at the engine start when a large amount of unburnt hydrocarbons are present in the exhaust gas. Further, the engine warm-up property of the automobile can be improved by the heat generated by the catalytic reaction of the hydrocarbons. The catalyst further exhibits a three-way catalytic activity even during the steady state engine operation after warm-up.
摘要:
A catalyst composition for purification of exhaust gas, including (a) high-silica zeolite having a Si/Al ratio of 40 or more, subjected to ion exchange with at least one metal selected from Pt, Pd, Rh, Ir and Ru, and (b) a heat-resistant oxide containing at least one metal selected from Pt, Pd, Rh, Ir and Ru; a catalyst for purification of exhaust gas, including a monolith carrier and the catalyst composition supported on the carrier; and a process for producing the catalyst. The catalyst has high activity for exhaust gas purification even when the catalyst contains Rh--, --, which is an expensive catalyst component, in a very small amount.
摘要:
A reformer is disposed in the flow path of a reactant fluid. The reformer includes an electrically heatable heater unit of honeycomb structure, in the upstream of the flow path of a reactant fluid, and a catalyst unit of honeycomb structure capable of generating hydrogen from a reactant fluid containing an organic compound or carbon monoxide, by catalysis, in the downstream of the above heater unit. The heater unit and catalyst unit satisfy the following relationship: Cell density of the heater unit≦Cell density of the catalyst unit. The reformer improve efficiency for production of hydrogen and reduce CO as the by-product.
摘要:
A carrier having a specific structure, characterized in that it has alumina and, optionally, a substance liable to react with an alkali metal and/or an alkaline earth metal both used as a catalyst component and/or an alkali metal and/or an alkaline earth metal, which are disposed in the carrier or on the cell wall surface of the carrier; a method for production of the carrier; and a catalyst body comprising the carrier and a catalytic material coated thereon. The use of the carrier allows production of a catalyst body which comprises the carrier and a catalytic material coated thereon, containing an alkali metal and/or an alkaline earth metal, such as Li, Na, K, Ca or the like and which is less susceptible to the deterioration of the carrier caused by the above metal even when used over a long period of time.
摘要:
A system for exhaust gas purification includes at least one adsorbent capable of adsorbing harmful substances such as hydrocarbons and the like in exhaust gas and at least one catalyst containing a catalyst component, capable of reducing said harmful substances, both provided at an in-line position of exhaust pipe of internal combustion engine. In the system, the hydrocarbons, etc. in the exhaust gas emitted during cold engine start up of internal combustion engine are adsorbed by the adsorbent and the adsorbed hydrocarbons, etc. are desorbed from the adsorbent with the temperature rise of the adsorbent caused by the heat of the exhaust gas and are burnt on the catalyst. The adsorbent contains a H type β-zeolite having a SiO2/Al2O3 ratio of 100 or more and can maintain good adsorption capability even when exposed to an exhaust gas of 750° C. or more form an internal combustion engine. This system for exhaust gas purification can effectively purify harmful substances in exhaust gas, particularly the hydrocarbons, etc. emitted in large amounts during cold engine start up.
摘要翻译:废气净化系统包括至少一种能够吸附排气中的烃等有害物质的吸附剂,以及至少含有催化剂成分的能够还原所述有害物质的催化剂,两者均设置在排列位置 的内燃机排气管。 在该系统中,在内燃机的冷启动发动机期间排出的废气中的碳氢化合物等被吸附剂吸附,吸附的烃等从吸附剂中脱附,伴随着吸附剂的升温 废气的热量并在催化剂上燃烧。 该吸附剂含有具有100或更大的SiO 2 / Al 2 O 3比率的H型β-沸石,并且可以保持良好的吸附能力 即使暴露于750℃以上的废气也形成内燃机。 该排气净化系统能够有效地净化排气中的有害物质,特别是发动机冷启动时大量排放的烃类等。
摘要:
A catalyst body comprising a carrier and a catalyst layer containing an alkali metal and/or an alkaline earth metal, loaded on the carrier, which catalyst further contains a substance capable of reacting with the alkali metal and/or the alkaline earth metal, dominating over the reaction between the main components of the carrier and the alkali metal and/or the alkaline earth metal. With this catalyst body, the deterioration of the carrier by the alkali metal and/or the alkaline earth metal is prevented; therefore, the catalyst body can be used over a long period of time.
摘要:
A honeycomb structure 1 having numerous through channels passing through along the X axis and being partitioned with porous partition walls 2 which is characterized in that: a total pore volume (D) cc/g in end portions of the partition walls 2 is smaller than the total pore volume in other portions of partition walls 2; and relationships between the total pore volume (D) cc/g in end portions and the partition wall thickness (B) μm and cell pitch (C) mm in other portions of partition walls are defined as; the total pore volume (D)≦the partition wall thickness (B)×0.004, and the total pore volume (D)≦(1/the cell pitch (C))×0.18; and a method of producing a honeycomb structure. There is provided with the honeycomb structures 1 having various cell structures and being reinforced at their end portions, with exhibiting satisfactory and practical erosion resistance.