Inorganic Chemicals Industry ›› 2022, Vol. 54 ›› Issue (3): 119-124.doi: 10.19964/j.issn.1006-4990.2021-0368

• Catalytic Materials • Previous Articles     Next Articles

Study on preparation of hierarchical ZSM-5/SAPO-34 composite molecular sieve and its MTO performance

WANG Yinzhong(),QIN Dongling,YANG Gang()   

  1. State Key Laboratory of Materials-Oriented Chemical Engineering,College of Chemical Engineering,Nanjing Tech University,Nanjing 211800,China
  • Received:2021-07-07 Online:2022-03-10 Published:2022-03-18
  • Contact: YANG Gang E-mail:wangyinzhong@njtech.edu.cn;yanggang@njtech.edu.cn

Abstract:

In order to prepare MTO catalysts with better performance and further investigate the effect of multi-level pores on the catalytic reaction of MTO,ZSM-5/SAPO-34 composite molecular sieve(CA-Z-S) with multi-level pore structure was successfully prepared by etching the composite molecular sieve with citric acid solution(CA) using post-treatment method. The physicochemical properties of the composite molecular sieve,such as crystalline phase,skeleton and pore structure,were also characterized.The composite molecular sieve was used for catalytic methanol-to-olefin(MTO) reaction and its catalytic performance was investigated.The characterization results showed that the treatment with CA would have effect on the morpho-logical structure of the ZSM-5/SAPO-34 composite molecular sieve,resulting in a more compact composite structure,a mod-erate amount of weak acid centers and a multi-level pore composite structure of CA-Z-S.The catalytic test results showed that the lifetime of CA-Z-S was 1 200 min at 100% methanol conversion,which was 79% higher than that of SAPO-34 and 30% higher than that of ZSM-5/SAPO-34.The selectivity of CA-Z-S for light olefins reached 90.5%,which was about 3.7% higher than that of SAPO-34.The results indicated that the post-treatment of the composite molecular sieve with CA was beneficial to the performance of the composite molecular sieve catalyzed MTO reaction.

Key words: SAPO-34, ZSM-5, composite molecular sieve, MTO reaction

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