THE USE OF THE COMBINATION OF FTIR, PYRIDINE ADSORPTION, 27Al AND 29Si MAS NMR TO DETERMINE THE BRÖNSTED AND LEWIS ACIDIC SITES
DOI:
https://doi.org/10.11113/jt.v78.8821Keywords:
Lewis acidic sites, Brönsted acidic sites, ZSM-5, kaolin, silica defects, molar ratios Si/Al, pyridine adsorptionAbstract
Lewis and Brönsted acidity were studied on ZSM-5 with combination of pyridine adsorption and FTIR vibration, ZSM-5 synthesized using kaolin Bangka Indonesia with an increase in the molar ratio of Si/Al 30-60 without pre-treatment and without organic templates and with seeds silicalite. Interestingly, the intensity of the infrared showed an increase of band vibration pyridine as absorbed Brönsted and Lewis acid sites in a molar ratio increase of Si/Al in ZSM-5, indicating an increase in the number of silanol (Brönsted acid) and deformed silica (Lewis acid) because the amount of Aluminum in ZSM-5 decrease with increase Si/Al but amount acidity increase. 29Si and 27Al MAS NMR analysis was supported by the results of infrared to indicate that all of the aluminum atom is coordinated with their neighbors are the same in ordering the ZSM-5 framework and 27Al MAS NMR showed a sharp peak of all the variations of Si/Al except the Si/Al 30 shows a low peak area. XRD analysis supported that the ZSM-5 structure formed is pure and crystal and a decrease in crystallinity proven for more than Si/Al 50, that defects silica occurs in ZSM-5, this corresponds to the growing number of Lewis acid sites caused by defects silica described the infrared results.
References
DÄ›deÄek, J., SobalÃk, Z., and Wichterlová, B. 2012. Siting and Distribution of Framework Aluminium Atoms in silicon-rich Zeolites and Impact on Catalysis. Catalysis Reviews: Science Engineering. 54(2): 135-223.
Brodu, N., Manero, M.-H., Andriantsiferana, C., Pic, J.-S., and Valdés, H. 2013. Role of Lewis Acid Sites of ZSM-5 Zeolite on Gaseous Ozone Abatement. Chemical Engineering Journal. 231: 281-286.
Banihashemi, F., Pakizeh, M., and Ahmadpour, A. 2011. CO2 Separation using PDMS/ZSM-5 Zeolite Composite Membrane. Separation and Purification Technology. 79: 293-302.
Ackley, M. W., Rege, S. U., and Saxena, H. 2003. Application of Natural Zeolites in the Purification and Separation of Gases. Microporous and Mesoporous Materials. 61: 25-42.
Nur, H., Ramli, Z., Efendi, J., Rahman, A.N.A., Chandren, S., and Yuan, L.S. 2011. Synergistic Role of Lewis and Brönsted Acidities in Friedel-Crafts Alkylation of Resorcinol over Gallium-zeolite Beta. Catalysis Communnications. 12: 822-825.
Abdmeziem, K., and Siffert, B. 1994. Synthesis of Large Crystals of ZSM-5 Zeolite from a Smectite-type Clay Material. Applied Clay Science. 8: 437-447.
Hartanto, D., Saputro, O., Utomo, W. P., Rosyidah, A., Sugiarso, D., Ersam, T., Nur, H., and Prasetyoko, D. 2015. Synthesis of ZSM-5 Directly from Kaolin Without Organic Template: Part-1: Effect of Crystallization Time. Asian Journal of Chemistry. 27(12): 1-5.
Can Li and Zili Wu. Handbook of Zeolite Science and Technology. 2003. In Scott M. Auerbach, Kathleen A. Carrado, and Prabir K. Dutta Microporous Materials Characterized by Vibrational Spectroscopies. New York, Basel: Marceld Ekkeirnc.
Savitri, Nasikin, M., Rinaldi, N., and Ramdani, D. 2013. Synthesis Of Cumene (Isopropyl Benzene) From Rosin Oil Through Cracking And Dehydrogenation. Teknologi Indonesia. 36(3): 154-160.
Amin, N. A., and Anggoro, D. 2003. Characterization and Activity of Cr, Cu and Ga Modified ZSM-5 for Direct Conversion of Methane to Liquid Hydrocarbons, Journal of Natural Gas Chemistry. 12: 123-134.
Yuan, L. S., Efendi, J., Razali, N. S. H., and Nur, H. 2012. Fine-tuning the Local Structure and Catalytic Activity of Titanium-amine Functionalized Silica in Oxidation of Limonene by Aqueous Hydrogen Peroxide. Catalysis Communications. 20: 85-8.
Mesa, M., Ramirez, A, Guth, J.-L. and Sierra, L. 2004. Adaption of Silanol Groups in Mesoporous Silica to be Silylated and Their Evaluation by FTIR. Study in Surface Science and Catalysis. 154L: 562-567.
Rimola, A., Costa, D., Sodupe, M., Lambert, J.-F., and Ugliengo, P. 2013. Silica Surface Features and Their Role in the Adsorption of Biomolecules: Computational Modeling and Experiments. Chemicals Review. 113: 4216-4313.
Van Bekkum, H., Flanigen, E. M., Jacobs, P. A., Jansen, J. C. 2001. Introduction to Zeolite Science and Pratice, Study in Surface sciences and Catalysis. 137: 370-373.
Grey, C. P. Handbook of Zeolite Science and Technology. 2003. In Auerbach, S. M., Carrado, K.A. and Dutta, P. K. Nuclear Magnetic Resonance Studies of Zeolites. New York, Basel: Marceld Ekkeirnc.
Sklenak, S., DÄ›deÄek, J., Li, C., Wichterlova, B., Gabova, V , Sierka, M., and Sauer, J. 2009, Aluminium siting in the ZSM-5 Framework By Combination Of High Resolution Al NMR and DFT/MM Calculations. Physical Chemistry Chemical Physics. 11: 1237-1247.
Downloads
Published
Issue
Section
License
Copyright of articles that appear in Jurnal Teknologi belongs exclusively to Penerbit Universiti Teknologi Malaysia (Penerbit UTM Press). This copyright covers the rights to reproduce the article, including reprints, electronic reproductions, or any other reproductions of similar nature.
