China Automotive Technology and Research Center Co. Ltd

Catarc Automotive Test Center (tianjin) Co., Ltd

Cheng Lv

Lingfeng Jia

Kaixiang Li

Yuankai Shao

Zhenguo Li

Jianhai Wang

Xiaoning Ren

Li Zhang

Zhixin Wu

Congjie Lv

Hanming Wu

An H-type molecular sieve having the CHA framework type is directly prepared through hydrothermal synthesis by using the compounds with the chemical formulas (CHNO)PO and/or (CHNO)PO(CHN) as structure-directing agents. The structure-directing agent has a molecular topological structure, which is conducive to quickly and efficiently building a molecular sieve having the CHA framework type, so that the prepared product has a regular morphology and high relative crystallinity. The synthesis method can directly synthesize the H-type molecular sieve having the CHA framework type with a relative crystallinity greater than 95%. The molecular sieve product can be obtained by direct drying and calcination without an ammonium exchange process, so the synthesis method is simple, easy to perform, and suitable for large-scale production. The samarium-based CHA molecular sieve catalyst shows excellent ammonia adsorption capacity, low-temperature activity, active temperature window, Nselectivity, and structural stability in the NH-SCR technology.

Synthesis method for directly preparing H-type molecular sieve having CHA framework type and use thereof

The present disclosure provides msect-4 molecular sieves with OFF and ERI topologies, a preparation method therefor, and applications thereof. An eight-membered ring small pore molecular sieve used as a raw material is dispersed in an aqueous phase. Following that, caustic potash, an aluminum source, and an organic structure-directing agent (OSDA) are added. The pH value is then adjusted to be greater than 10, and a silicon source is introduced to attain the desired silicon-aluminum ratio, followed by stirring reaction, aging, crystallization, filtration, washing, ammonia exchange reaction, drying, and calcination. The msect-4 molecular sieves with OFF and ERI topologies, the preparation method therefor, and applications exhibit excellent hydrothermal stability, a plurality of adsorption sites exposed by a regular bone-like structure, and a large specific surface area. Consequently, this molecular sieves find applicability across various technical fields including selective catalytic reduction, passive adsorption, and catalytic cracking, and has broad application prospects.

MSECT-4 molecular sieves with off and ERI topologies, preparation method therefor, and applications thereof

The present disclosure provides molecular sieves with intergrown phases of AEI and CHA topologies and a catalyst thereof. A preparation method for the molecular sieves include the following steps: mixing a hydroxyphosphono organic alkali R with an aluminum source and a silicon source to obtain a sol-gel precursor, putting the sol-gel precursor into a closed hydrothermal synthesis reactor for reaction, filtering the reaction solution, washing, drying, and calcination to obtain the molecular sieves with intergrown phases of AEI and CHA topologies. The molecular sieves and the catalyst thereof can be directly synthesized under mild conditions with a hydroxyphosphono organic alkali as a structure-directing agent and a phosphorus source, have a pH value of 6-9 and low requirements for corrosion resistance of production devices, and are suitable for large-scale production.

Molecular sieves with intergrown phases of AEI and CHA topologies and catalyst thereof

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Tianjin, China

Cheng Lv