Synthesis and catalytic uses of embryonic zeolites possessing acidic ou basic sites

• Grant number: 17/21965-5
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Effective date (Start): March 01, 2018
• Effective date (End): July 31, 2022
• Field of knowledge: Engineering - Chemical Engineering - Chemical Technology
• Principal Investigator: Leandro Martins
• Grantee: Laura Lorena da Silva
• Host Institution: Instituto de Química (IQ). Universidade Estadual Paulista (UNESP). Campus de Araraquara. Araraquara , SP, Brazil
• Associated scholarship(s): 18/20670-4 - MFI and FAU embryonic embryonic zeolites: synthesis and catalytic properties, BE.EP.PD

Abstract

Zeolites are an important class of materials with diverse applications, among them the use in heterogeneous basic or acid catalysis, depending on the control of the physical and chemical properties during or after its synthesis. Several modifications have been extensively studied, and currently embryonic zeolites appear as a new line of research to be explored. In this sense, the choice of this theme is based on the improvements in the catalytic activity of the embryonic zeolites of the MFI and FAU structure as described in the literature. In addition to the potential for the use of these materials in various reactions catalyzed by basic or acidic sites, including in the petrochemical industry, there are still numerous synthesis conditions not evaluated in the kinetic study of its formation. Therefore, the present work aims to enlarge the synthesis parameters in order to obtain the embryonic zeolites with different Si/Al ratios and to evaluate the accessibility, activity and stability of their acid or basic sites. Embryonic zeolites will be synthesized by evaluating the time, the temperature of synthesis and aging, the precursors and later characterized to establish the relation synthesis property-function in order to find embryonic structures with specific application to certain catalytic functions. For the characterizations, the techniques of X-ray diffractometric, electron diffraction, nuclear magnetic resonance of 27Al and 29Si, N2 physisorption, small angle X-ray scattering in situ or in operando, Fourier transform infrared spectroscopy, dispersive energy spectroscopy, desorption at programmed temperature of NH3, Spectroscopy photoelectronic X-ray and scanning electron microscopy will be used. Finally, the catalytic activity of the embryonic and of the crystalline zeolites will be evaluated through three reactions (esterification between acetic acid and isoamyl alcohol, acetalisation of glycerol with butyraldehyde, and Knoevenagel reaction between butyraldehyde and ethyl cyanoacetate). Thus, the structural and morphological characteristics, as well as the chemical composition of each zeolite, can be evaluated and correlated to catalytic activity, accessibility to acid or basic sites and stability. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

SILVA, LAURA LORENA; CARDOSO, DILSON; SIEVERS, CARSTEN; MARTINS, LEANDRO. Evolution of Structure and Active Sites during the Synthesis of ZSM-5: From Amorphous to Fully Grown Structure. Journal of Physical Chemistry C, v. 124, n. 4, p. 2439-2449, JAN 30 2020. (18/01258-5, 18/03710-2, 17/21965-5, 18/20670-4)