Comparative Study between Direct and Pseudomorphic Transformation of Rice Husk Ash into MFI-Type Zeolite.

Autor: Alyosef HA; Institute of Chemical Technology, Universität Leipzig, Linnéstr. 3, 04103 Leipzig, Germany. hallah.alyosef81@gmail.com., Roggendorf H; Institute of Physics, Martin-Luther-University Halle-Wittenberg, 06120 Halle (Saale), Germany. hans.roggendorf@physik.uni-halle.de., Schneider D; Institute of Chemical Technology, Universität Leipzig, Linnéstr. 3, 04103 Leipzig, Germany. denise.schneider@uni-leipzig.de., Inayat A; Institute of Chemical Reaction Engineering, Friedrich-Alexander University Erlangen-Nürnberg (FAU), Egerlandstr. 3, 91058 Erlangen, Germany. alexandra.inayat@fau.de., Welscher J; Institute of Chemical Reaction Engineering, Friedrich-Alexander University Erlangen-Nürnberg (FAU), Egerlandstr. 3, 91058 Erlangen, Germany. julia.welscher@fau.de., Schwieger W; Institute of Chemical Reaction Engineering, Friedrich-Alexander University Erlangen-Nürnberg (FAU), Egerlandstr. 3, 91058 Erlangen, Germany. wilhelm.schwieger@fau.de., Münster T; Institute of Mineralogy, Crystallography and Materials Science, Universität Leipzig, Scharnhorststrasse 20, 04275 Leipzig, Germany. tom.muenster@gmx.de., Kloess G; Institute of Mineralogy, Crystallography and Materials Science, Universität Leipzig, Scharnhorststrasse 20, 04275 Leipzig, Germany. kloess@uni-leipzig.de., Ibrahim S; Central Metallurgical Research & Development Institute (CMRDI), P.O. Box 87, Helwan 11421, Egypt. suzansibrahim@gmail.com., Enke D; Institute of Chemical Technology, Universität Leipzig, Linnéstr. 3, 04103 Leipzig, Germany. dirk.enke@uni-leipzig.de.
Jazyk: angličtina
Zdroj: Molecules (Basel, Switzerland) [Molecules] 2017 Dec 21; Vol. 23 (1). Date of Electronic Publication: 2017 Dec 21.
DOI: 10.3390/molecules23010001
Abstrakt: Pre-shaped mesoporous amorphous rice husk ash (RHA) and MCM-41 derived from RHA as a silica source were transformed into MFI-type zeolites using two different structure-directing agents. Tetrapropylammonium hydroxide (TPAOH) was utilized as an alkali source for silica dissolution and structure control during the direct transformation of RHA into zeolite. A monopropylamine (PA)-containing alkaline solution (NaOH) was used for the pseudomorphic transformation of RHA or MCM-41 into zeolite. The hydrothermal conversion of RHA or MCM-41 into MFI-type zeolites was investigated as a function of reaction time at 175 °C. With PA as template, the crystallization took place inside and on the outer surface of RHA or MCM-41 without losing the original shape of the initial silica sources, while TPAOH led to the formation of conventional MFI-type zeolite crystals due to the complete dissolution of RHA. The final products were characterized by X-ray diffraction, nitrogen adsorption, scanning electron microscopy, and optical emission spectroscopy.
Competing Interests: The authors declare no conflict of interest. The founding sponsors had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, and in the decision to publish the results.
Databáze: MEDLINE
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