The invention relates to a molecular sieve SCM-14, a preparation process and use thereof. The molecular sieve has a schematic chemical composition of a formula of SiO.sub.2.1/nGeO.sub.2 or a formula of kF.mQ.SiO.sub.2.1/nGeO.sub.2.pH.sub.2O, wherein the molar ratio of silicon to germanium, n, satisfies n30, and other values and symbols are defined in the specification. The molecular sieve has unique XRD diffraction data and can be used as an adsorbent or a catalyst.

A molecular sieve having the framework structure of ZSM-5 is described comprising crystals having an external surface area in excess of 100 m.sup.2/g (as determined by the t-plot method for nitrogen physisorption) and a unique X-ray diffraction pattern.

The invention concerns a process for preparing a copper-comprising microporous aluminosilicate material with AFX structure, comprising at least the steps of mixing, in an aqueous medium, at least one aluminum source, at least one silicon source, at least one copper source, a TETA or TEPA organic complexing agent and a DABCO-C4 structuring agent, in order to obtain a gel, and hydrothermal treatment of said gel with stirring in order to obtain crystallization of said copper-comprising microporous aluminosilicate material with AFX structure.

The invention concerns a process for preparing a copper-comprising microporous aluminosilicate material with AFX structure, comprising at least the steps of mixing, in an aqueous medium, at least one aluminum source, at least one silicon source, at least one copper source, a TETA or TEPA organic complexing agent and a DABCO-C4 structuring agent, in order to obtain a gel, and hydrothermal treatment of said gel with stirring in order to obtain crystallization of said copper-comprising microporous aluminosilicate material with AFX structure.

Compositions and methods for preparing mesoporous and/or mesostructured materials from low SAR zeolites are provided herewith. In particular, methods are provided that involve: (a) providing a low SAR zeolite, (b) optionally subjecting the low SAR zeolite to an acid framework modification, and (c) subjecting the framework-modified zeolite to a mesopore formation treatment. The resulting mesoporous zeolites can have bi-modal mesoporosity and higher aluminum contents relative to existing mesoporous zeolites.

Compositions and methods for preparing mesoporous and/or mesostructured materials from low SAR zeolites are provided herewith. In particular, methods are provided that involve: (a) providing a low SAR zeolite, (b) optionally subjecting the low SAR zeolite to an acid framework modification, and (c) subjecting the framework-modified zeolite to a mesopore formation treatment. The resulting mesoporous zeolites can have bi-modal mesoporosity and higher aluminum contents relative to existing mesoporous zeolites.

A copper-CHA zeolite catalyst for SCR of NO.sub.x is disclosed.

A catalyst and process for the production of methyl acetate by contacting dimethyl ether and carbon monoxide in the presence of a catalyst which is a zeolite of micropore volume of 0.01 ml/g or less.

Provided are zeolite catalysts that allow reactions to proceed at temperatures as low as possible when lower olefins are produced from hydrocarbon feedstocks with low boiling points such as light naphtha, make it possible to make propylene yield higher than ethylene yield in the production of lower olefins, and have long lifetime. The zeolite catalysts are used in the production of lower olefins from hydrocarbon feedstocks with low boiling points such as light naphtha. The zeolite catalysts are MFI-type crystalline aluminosilicates containing iron atoms and have molar ratios of iron atoms to total moles of iron atoms and aluminum atoms in the range from 0.4 to 0.7. The use of the zeolite catalysts make it possible to increase propylene yield, to lower reaction temperatures, and to extend catalyst lifetime.

The present disclosure provides a sound absorbing material. The sound absorbing material comprises MFI-structural-type zeolite. The MFI-structural-type zeolite comprises a framework, and the framework comprises SiO.sub.2 and AlO.sub.3, and the mass ratio of Si to Al in the framework is less than 200 and not less than 50. The present disclosure also provides a speaker box applying the sound absorbing material. The sound absorbing material provided by the present disclosure and the speaker box using the sound absorbing material can further improve the performance of the speaker box, reduce the failure of zeolite and improve the performance stability of the speaker box.