Synthesis and characterization of zeolites MTT and MFI, with controlled morphologies using mixed structure directing agents

•Zeolite MFI and MTT synthesis using HMPD and TMPD, respectively.•Mixed SDAs resulted in the controlled morphology.•The obtained morphology affected the adsorption characteristics of CO2.•Zeolite morphology was tailored systematically.

Morphologies of zeolites MFI and MTT were controlled using mixed structure directing agents (SDA), N1,N1,N3,N3-tetramethylpropane-1,3-diamine (TMPD) and N1,N1,N3,N3,2,2-hexamethylpropane-1,3-diamine (HMPD) during hydrothermal synthesis. The structure directing agents, TMPD and HMPD, led to the formation of zeolites MTT and MFI, respectively, because of the linear and branched molecular structure of each SDA. The location or the conformation of the SDA in the zeolite pore was investigated by combining the structure determination from synchrotron X-ray powder diffraction with the global optimization method. The presence of mixed SDAs in the hydrothermal synthesis significantly affected the morphologies of the zeolite. The one dimensional zeolite MTT showed the morphology of the three dimensional zeolite, MFI, when the ratio of the mixed SDA was changed.

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