Mesoporogen-free synthesis of hierarchical sodalite as a solid base catalyst from sub-molten salt-activated aluminosilicate--颗粒学报PARTICUOLOGY

Yang, J., Li, T., Bao, X., Yue, Y., & Liu, H. (2020). Mesoporogen-free synthesis of hierarchical sodalite as a solid base catalyst from sub-molten salt-activated aluminosilicate. Particuology, 48, 48-54. https://doi.org/10.1016/j.partic.2018.07.005

Mesoporogen-free synthesis of hierarchical sodalite as a solid base catalyst from sub-molten salt-activated aluminosilicate

Jinbiao Yang ^a¹, Tiesen Li ^{b 1}, Xiaojun Bao ^c, Yuanyuan Yue ^c *, Haiyan Liu ^a *

a State Key Laboratory of Heavy Oil Processing, China University of Petroleum, 18 Fuxue Road, Beijing 102249, China
b East-China Design Branch, China Petroleum Engineering & Construction Corporation, 2 Huayan Road, Qingdao 266071, China
c National Engineering Research Center of Chemical Fertilizer, College of Chemical Engineering, Fuzhou University, 2 Xueyuan Road, Fuzhou 350116, China

10.1016/j.partic.2018.07.005

Volume 48, February 2020, Pages 48-54

Received 19 June 2018, Revised 9 July 2018, Accepted 13 July 2018, Available online 21 December 2018, Version of Record 27 January 2020.

E-mail: yueyy@fzu.edu.cn; klc@cup.edu.cn

Highlights

• A novel route to prepare hierarchical sodalite from a natural mineral was developed.

• Mesoporogens, post-treatment, and Si- and Al-containing chemicals were not used.

• The rapid zeolitization was performed via the reversed crystal growth route.

• The resulting sodalite had hierarchical pore structure and high basicity.

• Sodalite-derived catalysts shown excellent performance in Knoevenagel condensation.

Abstract

A rapid and environmentally friendly approach to synthesize hierarchical sodalite from natural aluminosilicate mineral without the involvement of any mesoporogen or post-synthesis treatment was developed. This strategy involves three important steps: the first is the depolymerization of an aluminosilicate mineral into highly reactive silicon and aluminum species with ideal meso-scale structures through activation of a sub-molten salt. The second step is the hydrolysis and condensation of the activated aluminosilicate mineral into zeolitic precursors that also have a meso-scale structure. The third is the rapid zeolitization of the zeolitic precursors through the reversed crystal growth route at room temperature and ambient pressure to form hierarchical sodalite. The physicochemical properties of the as-synthesized sodalite were systematically characterized, and the formation mechanism of the hierarchical pore structure was discussed. When used as a solid base catalyst for Knoevenagel condensation, the as-synthesized sodalite and its potassium ion-exchanged product with hierarchical micro–meso–macroporous structure both exhibited high catalytic activity and product selectivity.

Graphical abstract

Keywords

Natural aluminosilicate mineral; Hierarchical sodalite; Reversed crystal growth route; Kirkendall effect; Solid base catalyst; Knoevenagel condensation

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