摘要:
The present invention relates to a hierarchical aluminosilicate ZSM-5 molecular sieve having a total pore volume of at least 0.85 cm3/g comprising mesopores having a diameter of 2-50 nm and micropores having a diameter of 0-2 nm. At least 50 percent of the mesopores have an open pore structure.5
摘要:
A process for converting ethylene to liquid fuel products utilizing a ZSM-5 catalyst that is essentially free of catalyst metals other than silica and alumina, where the catalyst has been subjected to a post-synthesis treatment comprising contacting the catalyst with a solution comprising at least one of an acid or a base to increase the resistance of the catalyst to accumulation of coke in the zeolite crystallite and extend catalyst life. The base treatment is provided by a weak sodium hydroxide of less than 1 Molar. The acid treatment comprises a hydrogen chloride solution exceeding 2 Molar.
摘要:
A method for the direct synthesis of a crystalline material with the AEI zeolithic structure containing iron-species and being essentially free of alkali ions, comprising the following steps: (i) preparation of a mixture containing water, a high-silica zeolite as a main source of silica and alumina, an alkyl-substituted cyclic ammonium cation as organic structure directing agent (OSDA), a source of iron, and a source of an alkali metal ion [Alk], to obtain a final synthesis mixture having the following molar composition: SiO 2 : a AI 2 O 3 : b Fe : c OSDA : d Alk : e H 2 O wherein a is in the range from 0.001 to 0.2; wherein b is in the range from 0.001 to 0.2; wherein c is in the range from 0.01 to 2; wherein d is in the range from 0.001 to 2; wherein e is in the range from 1 to 200; (ii) crystallization of the mixture achieved in (i); (iii) recovery of the crystalline material achieved in (ii); (iv) calcination of the crystalline material from step (iii); and (v) removal of the alkali metal cation, present in the calcined crystalline material after step (iv) to obtain a final molar composition: SiO 2 : o AI 2 O 3 : p Fe : q Alk wherein o is in the range from 0.001 to 0.2, p is in the range from 0.001 to 0.2 and q is below 0.02.
摘要:
The present disclosure relates to processes for formation of a molecular sieve, particularly a metal- promoted molecular sieve, and more particularly an Iron(III) exchanged zeolite. Preferably, the zeolite is of the chabazite form or similar structure. The processes can include combining a zeolite with Iron(III) cations in an aqueous medium. The process can be carried out at a pH of less than about 7, and a buffering material can be used with the aqueous medium. The processes beneficially result in Iron exchange that can approach 100% along with removal of cations (such as sodium, NH4, and H) from the zeolite. An Iron(III)-exchanged zeolite prepared according to the disclosed processes can include about 2,000 ppm or less of cation and about 1% by weight or greater of Iron(III). The disclosure also provides catalysts (e.g., SCR catalysts) and exhaust treatment systems including the Iron(III)-exchanged zeolite.
摘要:
An incipient wetness impregnation method for preparing a tin-containing zeolitic material having framework type BEA, a novel tin-containing zeolitic material having framework type BEA and its use.
摘要:
A method for the transformation of an alcohol into an olefin which comprises contacting said alcohol with a solid catalyst which comprises a zeolitic material of the FER type framework possessing a network of micropores which contains mesopores that are connected to the micropores, wherein the zeolitic material has a ratio of the volume of the mesopores contained within the network of micropores to the volume of the micropores in the range 0.1 to 2.
摘要:
The present invention relates to a new process for synthesising the silicoaluminate form of the AEI zeolite structure based on the use of another zeolite, zeolite Y, as the only source of silicon and aluminum, in order to obtain high synthesis yields (greater than 80%) in the absence of any other source of silicon, phosphine-derivedcationsand fluoride anions in the synthesis medium. The N,N-dimethyl-3,5-dimethylpiperidinium cation may be used as the OSDA, and the FAU crystal structure is transformed into the AEI crystal structure with high yields. It also discloses the preparation of catalysts based on the silicoaluminateform of the AEI crystal structure, wherein Cu atoms have been introduced, and the subsequent application thereof as a catalyst, preferably in the SCR of NOx.
摘要:
An organotemplate-free synthetic process is disclosed for the production of GME framework type zeolites by hydrothermal conversion of FAU framework type zeolites with sodium cations. The resulting zeolite product is substantially free of non-GME framework type material.