摘要:
Provided is an improved catalyst for treating exhaust gas, particularly for selectively reducing NOx, and methods for using the same, wherein the catalyst includes a blend of a transition metal promoted zeolite and an un-promoted zeolite, wherein both zeolites have the same framework type.
摘要:
A catalyst composition is provided having a CHA crystal structure; about 0.5 to about 5.0 mol % phosphorus; and SiO2 and Al2O3 in a mole ratio of about 5 to about 40. The catalyst composition is capable of NOx conversion at elevated temperatures. A catalytically active washcoat includes such catalyst compositions and one or more promoters or stabilizers, and may be applied to a monolith substrate to produce a catalytically active article. Methods of reducing NOx employing the catalyst compositions are also provided.
摘要翻译:提供具有CHA晶体结构的催化剂组合物; 约0.5至约5.0mol%的磷; 和摩尔比为约5至约40的SiO 2和Al 2 O 3。催化剂组合物能够在升高的温度下进行NOx转化。 催化活性的修补基面涂料包括这样的催化剂组合物和一种或多种促进剂或稳定剂,并且可以应用于整料基材以产生催化活性制品。 还提供了使用催化剂组合物还原NOx的方法。
摘要:
The present invention is directed to a process for preparing CHA-type molecular sieves using a colloidal aluminosilicate in the presence of a octahydroindolium-based cationic structure directing agent.
摘要:
Molecular sieves, improved methods for their synthesis, and catalysts, systems and methods of using these molecular sieves as catalysts in a variety of processes such as abating pollutants in exhaust gases and conversion processes are described. The molecular sieves are made using a tailored colloid including an alumina source, a silica source and a structure directing agent.
摘要:
Provided is a honeycomb structure which is suppressed in the occurrence of cracks and hydration degradation, while maintaining excellent NOx removal performance of SAPO. A honeycomb structure having a honeycomb unit that comprises two zeolite species and an inorganic binder, and that has a plurality of through holes arranged side by side with a partition wall therebetween to be extended in the longitudinal direction of the unit. This honeycomb structure is characterized in that one of the two zeolite species is silicoaluminophosphate (SAPO) having a composition ratio Si/(Si+Al+P) of 0.1-0.25, and the other is aluminosilicate (CHA) having a composition ratio Si/Al of 2-10.
摘要翻译:提供了抑制SAPO的优异的NOx去除性能的蜂窝结构体,其在发生裂纹和水化降解的同时被抑制。 一种具有蜂窝单元的蜂窝结构体,其包含两种沸石种类和无机粘合剂,并且具有并排布置的多个通孔,其间具有分隔壁,以在所述单元的纵向延伸。 该蜂窝结构体的特征在于,两种沸石种类之一是Si /(Si + Al + P)的组成比为0.1-0.25的硅铝磷酸盐(SAPO),另一种为硅/硅酸盐(CHA),其组成比为Si / Al 2-10。
摘要:
Provided are catalysts comprising a small pore molecular sieve embedded with platinum group metal (PGM) and methods for treating lean burn exhaust gas using the same.
摘要:
An oxidation catalyst for treating an exhaust gas from a diesel engine and an exhaust system comprising the oxidation catalyst are described. The oxidation catalyst comprises: a first washcoat region for oxidising carbon monoxide (CO) and hydrocarbons (HCs), wherein the first washcoat region comprises a first platinum group metal (PGM) and a first support material; a second washcoat region for oxidising nitric oxide (NO), wherein the second washcoat region comprises platinum (Pt), manganese (Mn) and a second support material; and a substrate having an inlet end and an outlet end; wherein the second washcoat region is arranged to contact the exhaust gas at the outlet end of the substrate and after contact of the exhaust gas with the first washcoat region.
摘要:
The present invention relates to a process for the preparation of zeolites having CHA framework structure and a composition comprising the molar ratio (n SiO2):X2O3, wherein X is a trivalent element, and wherein n is at least 10, the process comprising (i) preparation of an aqueous solution containing at least one source for X2O3, wherein X is selected from Al, B, Ga, and a mixture of two or more, and at least one source for SiO2, at least one organic structure directing agent (SDA) other than Tetramethylammonium hydroxide (TMAOH), acting as a template for the CHA structure, and Tetramethylammonium hydroxide (TMAOH), wherein the SDA or mixtures thereof are employed in such amounts that the aqueous solution in (i) exhibits a molar ratio of SDA:TMAOH of 0.01 to 5; (ii) hydrothermal crystallization of the aqueous solution according to (i); wherein the aqueous solution of (i) contains copper in an amount less than 0.005 Cu: ((n YO2)+X2O3) where n is in the range of 10 to 50. The present invention also relates to the zeolitic materials obtainable and/or obtained by this process as well as to a zeolitic material as such, having framework structure CHA, having a composition comprising the molar ratio (n SiO2):X2O3, wherein X is a trivalent element and n is at least 10, and wherein the crystal size, as determined from Scanning Electron Microscopy, is greater than 1 micrometer and wherein the chabazite framework is phase-pure having an impurity of other zeolitic frameworks, such as RUT as determined by X-ray Diffraction, of less than 5%.
摘要翻译:本发明涉及一种制备具有CHA骨架结构的沸石和包含摩尔比(n SiO 2):X 2 O 3的组合物的方法,其中X是三价元素,并且其中n至少为10,该方法包括(i )制备含有至少一种X 2 O 3的源的水溶液,其中X选自Al,B,Ga,以及两种或更多种的混合物和至少一种SiO 2源,至少一种有机结构导向剂(SDA ),作为CHA结构的模板的四甲基氢氧化铵(TMAOH)和氢氧化四甲基铵(TMAOH),其中SDA或其混合物的使用量使得(i)中的水溶液表现出的摩尔比为SDA :TMAOH为0.01〜5; (ii)根据(i)的水溶液的水热结晶; 其中(i)的水溶液含有小于0.005 Cu:((n YO 2)+ X 2 O 3)的铜,其中n在10至50的范围内。本发明还涉及可获得的和/或 通过该方法获得的沸石材料以及具有骨架结构CHA的沸石材料,其具有包含摩尔比(n SiO 2):X 2 O 3的组成,其中X是三价元素,n至少为10,并且其中晶体 通过扫描电子显微镜测定的尺寸大于1微米,其中菱沸石框架是相纯的,具有小于5%的其它沸石骨架的杂质,例如通过X射线衍射测定的RUT。
摘要:
A carbon dioxide adsorbent may include a chabazite zeolite containing an alkali metal ion or alkaline earth metal ion. The chabazite zeolite may have a Si/Al mole ratio of about 1 to about 9.9 and mesopores. The carbon dioxide adsorbent may be included in a carbon dioxide capture module. The carbon dioxide adsorbent may also be used in a method of separating carbon dioxide.
摘要:
A process for producing an aluminosilicate molecular sieve comprises crystallizing a reaction mixture comprising water, a source of silica and seeds of a silicoaluminophosphate and/or an aluminophosphate molecular sieve. The resultant aluminosilicate molecular sieve product can advantageously be substantially free of framework phosphorus.