摘要:
Aspects of the present invention relate to a process for the preparation of a zeolitic material having a CHA-type framework structure comprising YO2 and X2O3, wherein said process comprises the steps of: (1) providing a mixture comprising one or more sources for YO2, one or more sources for X2O3, and one or more tetraalkylammonium cation R1R2R3R4N+-containing compounds as structure directing agent; (2) crystallizing the mixture obtained in step (1) for obtaining a zeolitic material having a CHA-type framework structure; wherein Y is a tetravalent element and X is a trivalent element, wherein R1, R2, and R3 independently from one another stand for alkyl, wherein R4 stands for cycloalkyl, and wherein the mixture provided in step (1) does not contain any substantial amount of a source for Z2O5, wherein Z is P, as well as to zeolitic materials which may be obtained according to the inventive process and to their use.
摘要翻译:本发明的方面涉及制备具有包含YO 2和X 2 O 3的CHA型骨架结构的沸石材料的方法,其中所述方法包括以下步骤:(1)提供包含一种或多种YO 2, 一种或多种X2O3源和一种或多种四烷基铵阳离子R1R2R3R4N +化合物作为结构导向剂; (2)使步骤(1)中得到的混合物结晶得到具有CHA型骨架结构的沸石材料; 其中Y是四价元素,X是三价元素,其中R1,R2和R3彼此独立地代表烷基,其中R4代表环烷基,并且其中步骤(1)中提供的混合物不含任何实质的量 的Z 2 O 5的源,其中Z是P,以及可以根据本发明方法获得的沸石材料及其用途。
摘要:
Aspects of the present invention relate to an improved process for exchanging alkali metal or alkaline earth metal ions in zeolites for ammonium ions. For this exchange, aqueous solutions of ammonium salts, for example ammonium sulfate, ammonium nitrate or ammonium chloride, are currently being used. The resulting “ammonium zeolites” are calcined to convert them, with release of ammonia, to the H form of the zeolites suitable as a catalyst. Certain methods provided herein use ammonium carbonate instead of the ammonium compounds mentioned. As excess ammonium carbonate, in contrast to the nitrates, sulfates or chlorides, can be recycled in the form of carbon dioxide and ammonia, the amount of salt which has to be discharged is lowered significantly.
摘要:
The present invention relates to a process for the preparation of a zeolitic material having a CHA framework structure, said zeolitic material comprising zeolite crystals having a core-shell structure, wherein said process comprises the steps of (1) providing a mixture comprising one or more sources for Z2O5, one or more sources for X2O3, optionally one or more structure directing agents, and seed crystals having a CHA framework structure, wherein the CHA framework structure of the seed crystals comprises YO2, X2O3, and optionally Z2O5, and wherein the seed crystals have a diameter of 450 nm or greater; (2) crystallizing the mixture provided in (1) to afford zeolite crystals comprising a core of seed crystal provided in step (1) and a shell crystallized on the seed crystal; wherein Z is a pentavalent element, Y is a tetravalent element, and X is a trivalent element.
摘要翻译:本发明涉及一种制备具有CHA骨架结构的沸石材料的方法,所述沸石材料包含具有核 - 壳结构的沸石晶体,其中所述方法包括以下步骤:(1)提供包含一种或多种 Z 2 O 5的源,X 2 O 3,任选的一种或多种结构导向剂的一种或多种来源,以及具有CHA骨架结构的晶种,其中晶种的CHA骨架结构包含YO 2,X 2 O 3和任选的Z 2 O 5,并且其中所述种子 晶体的直径为450nm以上; (2)使(1)中提供的混合物结晶,得到包含步骤(1)中提供的晶种核心的沸石晶体和在晶种上结晶的壳; 其中Z为五价元素,Y为四价元素,X为三价元素。
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:
The present invention relates to application of catalysts for the Selective Catalytic Reduction of oxides of Nitrogen using N-containing reductant. The catalysts are characterised as phase pure lattice oxide materials into which catalytically active cations are incorporated at high levels of dispersion such that conventional analysis reveals a highly phase pure material. The materials are further characterised by high activity, hydrothermal durability and poison tolerance in the intended application.
摘要:
The synthesis of a crystalline material, in particular, a high silica zeolite, comprising a chabazite-type framework molecular sieve is conducted in the presence of an organic directing agent having the formula: [R1R2R3N—R4]+Q− wherein R1 and R2 are independently selected from hydrocarbyl groups and hydroxy-substituted hydrocarbyl groups having from 1 to 3 carbon atoms, provided that R1 and R2 may be joined to form a nitrogen-containing heterocyclic structure, R3 is an alkyl group having 2 to 4 carbon atoms and R4 is selected from a 4- to 8-membered cycloalkyl group, optionally, substituted by 1 to 3 alkyl groups each having from 1 to 3 carbon atoms; and a 4- to 8-membered heterocyclic group having from 1 to 3 heteroatoms, said heterocyclic group being, optionally, substituted by 1 to 3 alkyl groups each having from 1 to 3 carbon atoms and the or each heteroatom in said heterocyclic group being selected from the group consisting of O, N, and S, or R3 and R4 are hydrocarbyl groups having from 1 to 3 carbon atoms joined to form a nitrogen-containing heterocyclic structure; and Q− is a anion.
摘要:
The present invention is directed to a novel metal-promoted zeolite catalyst, a method of producing the catalyst and a method of using the catalyst for the selective catalytic reduction of NOx with improved hydrothermal durability. The novel metal-promoted zeolite is formed from a low sodium zeolite and is hydrothermally treated after metal ion-exchange.
摘要:
Disclosed are methods and compositions of synthesis mixtures for the synthesis of aluminophosphates and silicoaluminophosphate molecular sieves, which enable the control and adjustment of the crystal particle size of aluminophosphates and silicoaluminophosphate molecular sieves. The synthesis mixture compositions used have two or more organic templates present at a molar ratio of total template to aluminum of null1.25; such a synthesis mixture is susceptible to control of product particle size through variation in the amount of seeds used in the synthesis.
摘要:
This invention provides an attrition resistant catalyst composition and method for producing such composition. The catalyst is comprised of an acidic zeolite, rho or chabazite, and a particulate binder, kaolin, bentonite, alpha-alumina, or titania, which can be optionally modified by treatment with a compound containing Si, Al, P or B. This invention further provides a process for producing methylamines, preferably dimethylamine, comprising reacting methanol and/or dimethyl ether and ammonia in the presence of a catalytic amount of an attrition resistant catalyst of the invention.
摘要:
Aluminum from AlO.sub.4 -tetrahedra of as-synthesized zeolites is extracted and substituted with silicon to form zeolite compositions having higher SiO.sub.2 /Al.sub.2 O.sub.3 molar ratios and exhibiting distinctive chemical and physical properties. The preparative procedure involves contact of the starting zeolite with an aqueous solution of a fluorosilicate salt using controlled proportions and temperature and pH conditions which avoid aluminum extraction without silicon substitution.
摘要翻译:提取合成的沸石的AlO4-四面体的铝并用硅取代形成具有较高SiO 2 / Al 2 O 3摩尔比的沸石组合物并具有显着的化学和物理性能。 制备方法包括使用受控比例和温度和pH条件使起始沸石与氟硅酸盐水溶液接触,避免铝取代而不进行硅取代。