SCI和EI收录∣中国化工学会会刊

中国化学工程学报 ›› 2024, Vol. 65 ›› Issue (1): 75-84.DOI: 10.1016/j.cjche.2023.07.007

• Full Length Article • 上一篇    下一篇

Facile synthesis of hierarchical NaX zeolite from natural kaolinite for efficient Knoevenagel condensation

Wen Xiao1, Peng Dong1, Chan Wang1,2, Jingdong Xu3, Tiesen Li1,2, Haibo Zhu1,2, Tinghai Wang1,2, Renwei Xu3, Yuanyuan Yue1,2,   

  1. 1 National Engineering Research Center of Chemical Fertilizer Catalyst, College of Chemical Engineering, Fuzhou University, Fuzhou 350108, China;
    2 Qingyuan Innovation Laboratory, Quanzhou 362801, China;
    3 Sinochem Quanzhou Energy Technology Co., Ltd., Quanzhou 362000, China
  • 收稿日期:2023-04-07 修回日期:2023-07-23 出版日期:2024-01-28 发布日期:2024-04-17
  • 通讯作者: Renwei Xu,E-mail:xurenwei@sinochem.com;Yuanyuan Yue,E-mail:yueyy@fzu.edu.cn
  • 基金资助:
    The financial supports from the National Natural Science Foundation of China (22178059, 22208054 and 22072019), Natural Science Foundation of Fujian Province, China (2020J01513), Sinochem Quanzhou Energy Technology Co., Ltd. (ZHQZKJ-19-F-ZS- 0076) and Qingyuan Innovation Laboratory (00121002) are genuinely acknowledged.

Facile synthesis of hierarchical NaX zeolite from natural kaolinite for efficient Knoevenagel condensation

Wen Xiao1, Peng Dong1, Chan Wang1,2, Jingdong Xu3, Tiesen Li1,2, Haibo Zhu1,2, Tinghai Wang1,2, Renwei Xu3, Yuanyuan Yue1,2,   

  1. 1 National Engineering Research Center of Chemical Fertilizer Catalyst, College of Chemical Engineering, Fuzhou University, Fuzhou 350108, China;
    2 Qingyuan Innovation Laboratory, Quanzhou 362801, China;
    3 Sinochem Quanzhou Energy Technology Co., Ltd., Quanzhou 362000, China
  • Received:2023-04-07 Revised:2023-07-23 Online:2024-01-28 Published:2024-04-17
  • Contact: Renwei Xu,E-mail:xurenwei@sinochem.com;Yuanyuan Yue,E-mail:yueyy@fzu.edu.cn
  • Supported by:
    The financial supports from the National Natural Science Foundation of China (22178059, 22208054 and 22072019), Natural Science Foundation of Fujian Province, China (2020J01513), Sinochem Quanzhou Energy Technology Co., Ltd. (ZHQZKJ-19-F-ZS- 0076) and Qingyuan Innovation Laboratory (00121002) are genuinely acknowledged.

摘要: Zeolite catalysts have found extensive applications in the synthesis of various fine chemicals. However, the micropores of zeolites impose diffusion limitations on bulky molecules, greatly reducing the catalytic efficiency. Herein, we explore an economic and environmentally friendly method for synthesizing hierarchical NaX zeolite that exhibits improved catalytic performance in the Knoevenagel condensation reaction for producing the useful fine chemical 2-cyano-3-phenylacrylate. The synthesis was achieved via a low-temperature activation of kaolinite and subsequent in-situ transformation strategy without any template or seed. Systematic characterizations reveal that the synthesized NaX zeolite has both intercrystalline and intra-crystalline mesopores, smaller crystal size, and larger external specific surface area compared to commercial NaX zeolite. Detailed mechanism investigations show that the inter-crystalline mesopores are generated by stacking smaller crystals formed from in-situ crystallization of the depolymerized kaolinite, and the intra-crystalline mesopores are inherited from the pores in the depolymerized kaolinite. This synthesis strategy provides an energy-saving and effective way to construct hierarchical zeolites, which may gain wide applications in fine chemical manufacturing.

关键词: Hierarchical NaX zeolite, Template-free synthesis, Natural kaolinite, Knoevenagel condensation

Abstract: Zeolite catalysts have found extensive applications in the synthesis of various fine chemicals. However, the micropores of zeolites impose diffusion limitations on bulky molecules, greatly reducing the catalytic efficiency. Herein, we explore an economic and environmentally friendly method for synthesizing hierarchical NaX zeolite that exhibits improved catalytic performance in the Knoevenagel condensation reaction for producing the useful fine chemical 2-cyano-3-phenylacrylate. The synthesis was achieved via a low-temperature activation of kaolinite and subsequent in-situ transformation strategy without any template or seed. Systematic characterizations reveal that the synthesized NaX zeolite has both intercrystalline and intra-crystalline mesopores, smaller crystal size, and larger external specific surface area compared to commercial NaX zeolite. Detailed mechanism investigations show that the inter-crystalline mesopores are generated by stacking smaller crystals formed from in-situ crystallization of the depolymerized kaolinite, and the intra-crystalline mesopores are inherited from the pores in the depolymerized kaolinite. This synthesis strategy provides an energy-saving and effective way to construct hierarchical zeolites, which may gain wide applications in fine chemical manufacturing.

Key words: Hierarchical NaX zeolite, Template-free synthesis, Natural kaolinite, Knoevenagel condensation