Abstract:
Disclosed is a catalyst composition and its use in a process for the conversion of a feedstock containing C8+ aromatic hydrocarbons to produce light aromatic products, comprising benzene, toluene and xylene. The catalyst composition comprises a first zeolite having a constraint index of 3 to 12, a second zeolite comprising a mordenite zeolite synthesized from TEA or MTEA, at least one first metal of Group 10 of the IUPAC Periodic Table, and at least one second metal of Group 11 to 15 of the IUPAC Periodic Table, wherein said mordenite zeolite has a mesopore surface area of greater than 30 m2/g and said mordenite zeolite comprises agglomerates composed of primary crystallites, wherein said primary crystallites have an average primary crystal size as measured by TEM of less than 80 nm and an aspect ratio of less than 2.
Abstract:
A catalyst coating for use in a hydrolysis catalyst (H-catalyst) for the reduction of nitrogen oxides, a manufacturing method for such a coating, a catalyst structure and its use are described. The H-catalyst includes alkaline compounds, which are capable of adsorbing HNCO and/or nitrogen oxides and which include alkali and alkaline earth metals, lanthanum and/or yttrium and/or hafnium and/or prasedium and/or gallium, and/or zirconium for promoting reduction, such as for promoting the hydrolysis of urea and the formation of ammonia and/or the selective reduction of nitrogen oxides.
Abstract:
A method of manufacturing a catalyst body which includes: soaking at least part of a fired zeolite-based body in a transition metal oxide solution; removing the body from the transition metal oxide solution; exposing the body to a humidified atmosphere at one or more temperatures above 20° C.; then drying the body; and calcining the body.
Abstract:
An exhaust system, and a catalyzed substrate for use in an exhaust system, is disclosed. The exhaust system comprises a lean NO trap and the catalyzed substrate. The catalyzed substrate has a first zone, having a platinum group metal loaded on a support, and a second zone, having copper or iron loaded on a zeolite. The first zone or second zone additionally comprises a base metal oxide or a base metal loaded on an inorganic oxide. Also provided are methods for treating an exhaust gas from an internal combustion engine using the exhaust system. The exhaust system is capable of storing NH3 generated in rich purging, reacting the NH3 with slip NOX, controlling H2S released from NO trap desulfation, and oxidizing slip hydrocarbons and carbon monoxide. When the catalyzed substrate is a filter substrate, it is also capable of removing soot from exhaust system.
Abstract:
A method of manufacturing a catalyst body which includes: soaking at least part of a fired zeolite-based body in a transition metal oxide solution; removing the body from the transition metal oxide solution; exposing the body to a humidified atmosphere at one or more temperatures above 20° C.; then drying the body; and calcining the body.
Abstract:
The invention relates to a process for treating diesel engine exhaust gases comprising nitrogen oxides (NOx) and hydrocarbons (HC) by selective catalytic reduction of the nitrogen oxides with ammonia or a compound decomposable to ammonia as a reducing agent over an SCR catalyst based on a molecular sieve. The properties of the catalyst used are such that the hydrocarbons present in the exhaust gas are kept away from the catalytically active sites in the catalyst over which the reactions take place by the molecular sieve-like action of the zeolite present in the catalyst. This prevents HC-related degradation and aging effects of the SCR catalyst and achieves a considerable improvement in nitrogen oxide conversions in HC-containing exhaust gas.
Abstract:
There is disclosed iron-containing aluminosilicate zeolites having both framework iron and iron cations on the ion-exchange sites. There is also disclosed a direct synthesis method of making an iron-containing aluminosilicate zeolite, which does not require the use of an intermediate step, such as ion-exchange or impregnation. In addition, there is disclosed a method of using the iron-containing aluminosilicate zeolite disclosed herein in a selective catalytic reduction reaction, typically in the presence of ammonia, to reduce or remove nitric oxides from exhaust emissions.
Abstract:
A carbon monoxide selective oxidizing catalyst includes a carrier of ferrierite or ZSM-5 that supports a metal component of platinum (Pt) alone or platinum and at least one type of transition metal. Alternatively, a carbon monoxide selective oxidizing catalyst includes a carrier whose maximum pore diameter ranges from 0.55 to 0.65 nanometers (nm) that supports a metal component of platinum (Pt) alone or platinum and at least one type of transition metal.
Abstract:
The present invention provides a process for catalytically reducing nitrogen oxides in an exhaust gas stream containing nitrogen oxides and a reductant material by contacting the gas stream under conditions effective to catalytically reduce the nitrogen oxides with a catalyst comprising a aluminum-silicate type material and a minor amount of a metal, the catalyst characterized as having sufficient catalytic activity so as to reduce the nitrogen oxides by at least 60 percent under temperatures within the range of from about 200° C. to about 400° C.
Abstract:
The present invention provides a process for catalytically reducing nitrogen oxides in an exhaust gas stream containing nitrogen oxides and a reductant material by contacting the gas stream under conditions effective to catalytically reduce the nitrogen oxides with a catalyst comprising a aluminum-silicate type material and a minor amount of a metal, the catalyst characterized as having sufficient catalytic activity so as to reduce the nitrogen oxides by at least 60 percent under temperatures within the range of from about 200null C. to about 400null C.