Affiliation:
1. School of Chemistry and Chemical Engineering, Liaocheng University, Liaocheng 252000, China
2. State Key Laboratory of High-Efficiency Utilization of Coal and Green Chemical Engineering, College of Chemistry and Chemical Engineering, Ningxia University, Yinchuan 750021, China
Abstract
The morphology and porosity of zeolites have an important effect on adsorption and catalytic performance. In the work, simple inorganic salts, i.e., Na salts were used to synthesize MWW zeolite using the organic compound 1-Butyl-2,3-dimethyl-1H-imidazol-3-ium hydroxide as a structure-directing agent and the morphology was regulated by the alkali metals. The sample synthesized without Na salts shows a dense hexagon morphology, while different morphologies like ellipsoid, wool ball, and uniform hexagon appear when using NaOH, Na2CO3, and NaHCO3, respectively. Moreover, the impact of Na salts on the induction, nucleation, and the evolution of crystal growth was studied. Different kinds of Na salts have a different impact on the crystalline induction time in the order of NaHCO3 (36 h) < Na2CO3 (72 h) = NaOH (72 h). Meanwhile, the crystalline mechanism with the cooperation of inorganic salts and the organic SDAs is proposed. NaOH- and Na2CO3-MWW zeolite crystallized with a network of hydrogel via the nonclassical pathway in the system; however, the product is synthesized via a classical route in the NaHCO3 environment. This work provides information about MWW zeolite crystallization and modulating diverse morphologies by adjusting the process.
Funder
National Natural Science Foundation of China
Natural Science Foundation of Shandong Province
Guangyue Young Scholar Innovation Team of Liaocheng University
Innovation and Entrepreneurship Project for College Students of Liaocheng University
Subject
Chemistry (miscellaneous),Analytical Chemistry,Organic Chemistry,Physical and Theoretical Chemistry,Molecular Medicine,Drug Discovery,Pharmaceutical Science