Commenced in January 2007
Paper Count: 30982
Acidity of different Jordanian Clays characterized by TPD-NH3 and MBOH Conversion
Abstract:The acidity of different raw Jordanian clays containing zeolite, bentonite, red and white kaolinite and diatomite was characterized by means of temperature programmed desorption (TPD) of ammonia, conversion of 2-methyl-3-butyn-2-ol (MBOH), FTIR and BET-measurements. FTIR spectra proved presence of silanol and bridged hydroxyls on the clay surface. The number of acidic sites was calculated from experimental TPD-profiles. We observed the decrease of surface acidity correlates with the decrease of Si/Al ratio except for diatomite. On the TPD-plot for zeolite two maxima were registered due to different strength of surface acidic sites. Values of MBOH conversion, product yields and selectivity were calculated for the catalysis on Jordanian clays. We obtained that all clay samples are able to convert MBOH into a major product which is 3-methyl-3-buten-1-yne (MBYNE) catalyzed by acid surface sites with the selectivity close to 70%. There was found a correlation between MBOH conversion and acidity of clays determined by TPD-NH3, i.e. the higher the acidity the higher the conversion of MBOH. However, diatomite provided the lowest conversion of MBOH as result of poor polarization of silanol groups. Comparison of surface areas and conversions revealed the highest density of active sites for red kaolinite and the lowest for zeolite and diatomite.
Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1077713Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2903
 M. Frenke, "Surface acidity of montmorillonites," Clay Clay Miner., vol. 22, pp. 435- 441, 1974.
 L.I. Bel-chinskaya, O.Yu. Strel-nikova, L.A. Novikova, F. Roessner, O.V. Voishcheva, "Enhancement of the Adsorption Selectivity of Nanoporous Clinoptilolite by Hydrophobization with Organosiloxanes," Protect. Met.+, vol. 44, pp. 390-393, Apr. 2008.
 L. Rodr─▒guez-Gonzalez, F. Hermes, M. Bertmer, "The acid properties of H-ZSM-5 as studied by NH3-TPD and 27Al-MAS-NMR spectroscopy," Appl. Catal. A-Gen., vol. 328, pp. 174-182. 2007.
 L. M. Bull, A. K. Cheetham, T. Anupold, A. Reinhold, A. Samoson, J. Sauer, B. Bussemer, Y. Lee, S. Gann, J. Shore, A. Pines, R. Dupree, ÔÇ×A high-resolution (17)O NMR study of siliceous zeolite faujasite," J. Am. Chem. Soc., vol. 120, pp. 3510-3511. 1998.
 H. Knözinger, S. Huber, ÔÇ×Infrared Spectroscopy of Small and Weakly Interacting Molecular Probes for Acidic and Basic Zeolites," J. Chem. Soc. Farad. Trans., vol. 94, no. 15, pp. 2047-2059. 1998.
 M. Yurdakoc, M. Akcay, Y. Tonbul, K. Yurdakoc, ÔÇ×Acidity of silicaalumina catalysts by amine titration using Hammett indicators and FT-IR study of pyridine adsorption," Turk. J. Chem., vol. 23, no. 3, pp. 319- 327. 1999.
 M. A. Aramendia, Y. Aviles, J. A. Benitez, V. Borau, C. Jimenez, J. M. Marinas, J. R. Ruiz, F. J. Urbano, "Comparative Study of Mg/Al and Mg/Ga Layered Double Hydroxides," Micropor Mesopor Mat, 29, pp. 319-328. 1999.
 J. I. Di Cosimo, C. R. Apesteguia, M. J. L. Gines, E. Iglesia, ÔÇ×Structural Requirements and Reaction Pathways in Condensation Reactions of Alcohols on MgyAlOx Catalysts," J. Catal., vol. 190, no. 2, pp. 261-275. 2000.
 A. BorCave, A. Auroux, C. Guimon, "Nature and strength of acid sites in HY zeolites: a multitechnical approach," Microporous Mater., pp. 275-291, Nov. 1997.
 H. Lauron-Pernot, F. Luck, J. M. Popa, ÔÇ×Methylbutynol: a new and simple diagnostic tool for acidic and basic sites of solids," Appl. Catal., vol. 78, no. 2, pp. 213-225. 1991.
 Y. Ono, T. Baba, ÔÇ×Selective reactions over solid base catalysts," Catal. Today., vol. 38, no. 3, pp. 321-337. 1997.
 H. Lauron-Pernot, "Evaluation of surface acido-basic properties of inorganic-based solids by model catalytic alcohol reaction networks," Cat. Rev., vol. 48, pp. 315-361. 2006.
 M. Huang, S. Kaliaguine, "Reactions of methylbutynol on alkaliexchanged zeolites. A Lewis acid-base selectivity study," Catal. Lett., vol. 18, pp. 3373-389. 1993.
 U. Meyer, W. F. Hoelderich, ÔÇ×Application of basic zeolites in the decomposition reaction of 2-methyl-3-butyn-2-ol and the isomerization of 3-carene," J. Mol. Catal. A-Chem., vol. 142, no. 2, pp. 213-222. 1999.
 P. Kuśtrowski, L. Chmielarz, E. Bozek, M. Sawalha, F. Roessner, ÔÇ×Acidity and basicity of hydrotalcite derived mixed Mg-Al oxides studied by test reaction of MBOH conversion and temperature programmed desorption of NH3 and CO2," Mater. Res. Bull., vol. 39, no. 2, pp. 263-281. 2004.
 C. Chizallet, G. Costentin, H. Lauron-Pernot, J.M. Krafft, P. Bazin, J. Saussey, F. Delbecq, P., Sautet, M. Che, "Role of Hydroxyl Groups in the Basic Reactivity of MgO: a Theoretical and Experimental Study," Oil Gas Sci. Technol., vol. 61, no. 4, pp. 479-488. 2006.
 N. Abu Salah, A. Mehyar, K. Al-Rousan, M. Tarawneh, E. Nawasreh, Abu Arar, Natural Resources Authority, Arabic Report, Jordan. pp. 120- 126. 2002.
 M. Al-Ghouti, M.A.M. Khraisheh, S.J. Allen, M.N. Ahmad, "The removal of dyes from textile wastewater: a study of the physical characteristics and adsorption mechanisms of diatomaceous earth," J. Environ. Manage, vol. 69, pp. 229-238. 2003.
 M. Nawasreh, Y. Al. Omari, J. Sahawneh, M. Madanat, Natural resources Authority, Jordan, pp. 101-107. 2006.
 L.T. Zhuravlev, "The surface chemistry of amorphous silica. Zhuravlev model," Colloid. surface A, vol. 173, pp. 1-38. 2000.
 I. Rushdi Yousef, F. Maha Tutunji, A. Ghazi, W. Derwish, M. Salem Musleh, "Chemical and structural properties of Jordanian zeolitic tuffs and their admixtures with urea and thiourea: potential scavengers for phenolics in aqueous medium," J. Colloid Interf. Sci., vol. 216, pp. 348- 359. 1999.
 P. Yuan, D.Q. Wu, Z. Chen, Z. Lin, G. Diao, J. Peng, "1H MAS NMR spectra of hydroxyl species on diatomite surface," Chinese Sci. Bull., vol. 46, no. 13, pp. 1118-1121. 2001.
 P. Yuan, D.Q. Wu, H.P. He, Z.Y. Lin, "The hydroxyl species and acid sites on diatomite surface: a combined IR and Raman study," Appl. Surf. Sci., vol. 227, no. 1-4, pp. 30-39. 2004.
 B. Fubini, V. Bolis, A. Cavenago, M. Volantel, "Physicochemical properties of crystalline silica dusts and their possible implication in various biological responses," Scand. J. Work. Env. Hea., vol. 21, pp. 9- 14. 1995.
 M. Alsawalha, F. Roessner, ÔÇ×Insight in to the reaction mechanism of the conversion of methylbutynol on silica-alumina," React. Kinet. Catal. Lett., vol. 94, no. 1, pp. 63-69. 2008.