MRC  Vol.2 No.3 , July 2013
Catalytic Activity and Selectivity of Unsupported Dodecatungstophosphoric Acid, and Its Cesium and Potassium Salts Supported on Silica
Abstract: Potassium and cesium salts of tungstophosphoric acid were prepared by precipitation method. For sake of comparison HPW, potassium and cesium tungstophosphates were supported on silica (20 wt%) by wet impregnation method. The catalysts were characterized by XRD, nitrogen adsorption-desorption measurements at 77 K, and the catalytic activity has been studied by using the catalytic conversion of tert-butanol at temperatures between 323 and 423 K. The results revealed that all of the catalysts were active and selective towards dehydration of tert-butanol yielding isobutene with low amount of isooctene as result of oligomerization process. Substitution of one proton of HPW by cesium or potassium cation exerted no measurable effect on the catalytic activity. The conversion over unsupported catalysts increased by increasing the cation content per Keggin unit of x ≥ 2. Supporting the previous salts on SiO2 resulted in a significant decrease in the catalytic activity upon increasing cation content. Activation energy was calculated for different solids.
Cite this paper: S. Ibrahim, "Catalytic Activity and Selectivity of Unsupported Dodecatungstophosphoric Acid, and Its Cesium and Potassium Salts Supported on Silica," Modern Research in Catalysis, Vol. 2 No. 3, 2013, pp. 110-118. doi: 10.4236/mrc.2013.23016.

[1]   J. H. Sepulveda, J. C. Yori and C. R. Vera, “Repeated Use of Supported H3PW12O40 Catalysts in the Liquid Phase Esterification of Acetic Acid with Butanol,” Applied Catalysis A: General, Vol. 288, No. 1, 2005, pp. 18-24. doi:10.1016/j.apcata.2005.03.038

[2]   M. Misono, “A View on the Future of Mixed Oxide Catalysts: The Case of Heteropolyacids (Polyoxometalates) and Perovskites,” Catalysis Today, Vol. 100, No. 1-2, 2005, pp. 95-100. doi:10.1016/j.cattod.2004.12.010

[3]   K. N. Rao, K. M. Reddy, N. Lingaiah, I. Suryanarayana and P. S. Saiprasad, “Structure and Reactivity of Zirconium Oxide-Supported Ammonium Salt of 12-Molybdophosphoric Acid Catalysts,” Applied Catalysis A: General, Vol. 300, No. 2, 2006, pp. 139-146. doi:10.1016/j.apcata.2005.10.051

[4]   W. Kuang, A. Rives, M. Fournier and R. Hubaut, “Structure and Reactivity of Silica-Supported 12-Tungstophosphoric Acid,” Applied Catalysis A: General, Vol. 250, No. 2, 2003, pp. 221-229. doi:10.1016/S0926-860X(03)00239-4

[5]   T. Okuhara, N. Mizuno and M. Misono, “Catalytic Chemistry of Heteropoly Compounds,” Advances in Catalysis, Vol. 41, 1996, p. 113. doi:10.1016/S0360-0564(08)60041-3

[6]   I. V. Kozhevinkov and K. I. Matveev, “Homogeneous Catalysts Based on Heteropoly Acids,” Applied Catalysis A: General, Vol. 5, No. 2, 1983, p. 135. doi:10.1016/0166-9834(83)80128-6

[7]   A. N. Kharat, Ph. Pendleton, A. Badalyan, M. Abedini and M. M. Amini, “Oxidation of Aldehydes Using Silica-Supported Co(II)-Substituted Heteropolyacid,” Journal of Molecular Catalysis A: Chemical, Vol. 175, No. 1-2, 2001, pp. 277-283.

[8]   Y. Izumi, R. Hasebe and K. Urabe, “Catalysis by Hetero-Geneous Supported Heteropoly Acid,” Journal of Catalysis, Vol. 84, No. 2, 1983, p. 402. doi:10.1016/0021-9517(83)90011-8

[9]   M. Misono, “Recent Progress in the Practical Applications of Heteropoly Acid and Perovskite Catalysts: Catalytic Technology for the Sustainable Society,” Catalysis Today, Vol. 144, No. 3-4, 2009, pp. 285-291.

[10]   B. Bachiller-Baeza and J. A. Anderson, “FTIR and Reac-Tion Studies of the Acylation of Anisole with Acetic Anhydride over Supported HPA Catalysts,” Journal of Catalysis, Vol. 228, No. 1, 2004, pp. 225-233. doi:10.1016/j.jcat.2004.08.010

[11]   E. Lopez-Salinas, J. G. Hernandez-Cortez, I. Schifter, E. Torres-Garcia, J. Navarrete, A. Gutierrez-Carrillo, T. Lopez, P. P. Lottici and D. Bersani, “Thermal Stability of 12-Tungstophosphoric Acid Supported on Zirconia,” Applied Catalysis A: General, Vol. 193, No. 1, 2000, pp. 215-225. doi:10.1016/S0926-860X(99)00431-7

[12]   J. Haber, K. Pamin, L. Matachowski, B. Napruszews and J. Poltowicz, “Potassium and Silver Salts of Tungstophosphoric Acid as Catalysts in Dehydration of Ethanol and Hydration of Ethylene,” Journal of Catalysis, Vol. 207, No. 2, 2002, pp. 296-306. doi:10.1006/jcat.2002.3514

[13]   S. Choi, Y. Wang, Z. Nie, J. Liu and C. H. F. Peden, “Cs-Substituted Tungstophosphoric Acid Salt Supported on Mesoporous Silica,” Catalysis Today, Vol. 55, No. 1, 2000, pp. 117-124. doi:10.1016/S0920-5861(99)00231-X

[14]   J. H. Kim, Y. G. Shul and H. Han, “Synthesis of Heteropolyacid (H3PW12O40)/SiO2 Nanoparticles and Their Catalytic Properties,” Applied Catalysis A: General, Vol. 299, No. 1, 2006, pp. 46-51. doi:10.1016/j.apcata.2005.10.010

[15]   J. Haber, K. Pamin, L. Matachowski and D. Mucha, “Catalytic Performance of the Dodecatungstophosphoric Acid on Different Supports,” Applied Catalysis A: General, Vol. 256, No. 1, 2003, pp. 141-152. doi:10.1016/S0926-860X(03)00395-8

[16]   S. Soled, S. Miseo, G. McVicker, W. E. Gates, A. Gutierrez and J. Paes, “Preparation of Bulk and Supported Heteropolyacid Salts,” Catalysis Today, Vol. 36, No. 4, 1997, pp. 441-450. doi:10.1016/S0920-5861(96)00235-0

[17]   A. Alsalme1, E. F. Kozhevnikova and I. V. Kozhevnikov, “α-Pinene Isomerisation over Heteropoly Acid Catalysts in the Gas-Phase,” Applied Catalysis A, Vol. 390, No. 1-2, 2010, pp. 219-224.

[18]   S. K. Bhorodwaj and D. K. Dutta, “Activated Clay Supported Heteropoly Acid Catalysts for Esterification of Acetic Acid with Butanol,” Applied Clay Science, Vol. 53, No. 2, 2011, pp. 347-352. doi:10.1016/j.clay.2011.01.019

[19]   T. Okuhara, T. Nishimura and M. Misono, “Novel Mi-Croporous Solid ‘Super Acids’: CsxH3·xPW12O40 (2 ≤ x ≤ 3),” 11th International Congr. Catal., Baltimore, 1996, p. 581.

[20]   T. Okuhara, T. Nishimura, H. Watanabe, K. Na and M. Misono, “Catalysis of Cesium Salt of Heteropoly Acid and Its Characterization by Solid-State NMR,” Studies in Surface Science and Catalysis, Vol. 90, 1994, pp. 419-428. doi:10.1016/S0167-2991(08)61853-4

[21]   C. Travers, E. Essayem, M. Delage and S. Quelen, “Heteropolyanions Based Catalysts for Paraffins Isomerization,” Catalysis Today, Vol. 65, No. 2-4, 2001, pp. 355-361. doi:10.1016/S0920-5861(00)00590-3

[22]   A. Alhanash, E. F. Kozhevnikova and I. V. Kozhevnikov, “Gas-Phase Dehydration of Glycerol to Acrolein Catalysed by Caesium Heteropoly Salt,” Applied Catalysis A, Vol. 378, No. 1, 2010, pp. 11-18.

[23]   W. Yang, J. Billy, Y. B. Taarit, J. C. Vedrine and N. Essayem, “H3PW12O40 Supported on Cs Modified Mesoporous Silica: Catalytic Activity in n-Butane Isomerisation and in Situ FTIR Study: Comparison with Microporous CsxH3?xPW12O40,” Catalysis Today, Vol. 73, No. 1-2, 2002, pp. 153-165. doi:10.1016/S0920-5861(01)00508-9

[24]   L. R. Pizzio and M. N. Blanco, “Isoamyl Acetate Production Catalyzed by H3PW12O40 on Their Partially Substituted Cs or K Salts,” Applied Catalysis A: General, Vol. 255, No. 2, 2003, pp. 265-277. doi:10.1016/S0926-860X(03)00565-9

[25]   M. A. Parent and J. B. Moffat, “Cation/Proton Interactions and Acid Strengths in Salts of 12-Tungstophosphoric Acid Prepared from 1A, 1B and 3B Monovalent Cations,” Catalysis Letters, Vol. 48, No. 3-4, 1997, pp. 135-143. doi:10.1023/A:1019012128507

[26]   J. G. Highfield and J. B. Moffat, “Elucidation of the Mechanism of Dehydration of Methanol over 12-Tungstophosphoric Acid Using Infrared Photoacoustic Spectroscopy,” Journal of Catalysis, Vol. 95, No. 1, 1985, pp. 108-119. doi:10.1016/0021-9517(85)90012-0

[27]   M. Mizuno and M. Misono, “Heterogeneous Catalysis,” Chemical Reviews, Vol. 98, No. 1, 1998, pp. 199-218. doi:10.1021/cr960401q

[28]   Sh. M. Ibrahim and G. A. El-Shobaky, “Catalytic Efficiency of Cesium and Potassium Salts of Dodecatungstophosphoric Acid Supported on Silica and Comparison with H3PW12O40/SiO2,” Kinetics and Catalysis, Vol. 49, No. 4, 2008, pp. 507-515. doi:10.1134/S0023158408040058

[29]   I. V. Kozhevnikov, K. R. Kloestra, A. Sinnema, H. W. Zandbergen and H. Van Bekkum, “Study of Catalysts Comprising Heteropoly Acid H3PW12O40 Supported on MCM-41 Molecular Sieve and Amorphous Silica,” Journal of Molecular Catalysis A: Chemical, Vol. 114, No. 1-3, 1996, pp. 287-298. doi:10.1016/S1381-1169(96)00328-7

[30]   T. Blasco, A. Corma, A. Martinez and P. Martinez-Escolano, “Supported Heteropolyacid (HPW) Catalysts for the Continuous Alkylation of Isobutane with 2-Butene: The Benefit of Using MCM-41 with Larger Pore Diameters,” Journal of Catalysis, Vol. 177, No. 2, 1996, pp. 306-313. doi:10.1006/jcat.1998.2105

[31]   K. Saita, M. Nomura, S. Ohgoshi and Y. Akai, “Symposium on Solid Super Acids: Synthesis, Characterization and Catalysis,” Proceedings of the 214th National Meeting, Nevada, 7-11 September 1997.

[32]   Z. Zhao, W. Ahn and R. Ryoo, “Preparation, Characterization and Catalytic Activity of Heteropolyacids Supported on Mesoporous Silica and Carbon,” Studies in Surface Science and Catalysis, Vol. 146, 2003, pp. 657-660. doi:10.1016/S0167-2991(03)80469-X

[33]   L. R. Pizzio, C. V. Caceres and M. N. Blanco, “Acid Catalysts Prepared by Impregnation of Tungstophosphoric Acid Solutions on Different Supports,” Applied Catalysis A: General, Vol. 167, No. 2, 1998, pp. 283-294. doi:10.1016/S0926-860X(97)00328-1

[34]   M. M. Mastikhin and S. M. Timofeeva, “1H and 31P MAS NMR Studies of Solid Heteropolyacids and H3PW12O40 Supported on SiO2,” Journal of Molecular Catalysis, Vol. 60, No. 1, 1990, pp. 65-70. doi:10.1016/0304-5102(90)85068-S

[35]   F. Lefebvre, “31P MAS NMR Study of H3PW12O40 Supported on Silica: Formation of (SiOH2+)(H2PW12O40–),” Journal of the Chemical Society, Chemical Communications, No. 10, 1992, pp. 756-757. doi:10.1039/c39920000756

[36]   J. B. Moffat and S. Kasztelan, “The Oxidation of Methane on Heteropolyoxometalates II. Nature and Stability of the Supported Species,” Journal of Catalysis, Vol. 109, No. 1, 1988, pp. 206-211. doi:10.1016/0021-9517(88)90199-6

[37]   C. Rocchiccioli-Deltcheff, M. Amirouche, G. Herve, M. Fournier, M. Che and J. M. Tatibouet, “Structure and Catalytic Properties of Silica-Supported Polyoxomolybdates: II. Thermal Behavior of Unsupported and Silica-Supported 12-Molybdosilicic Acid Catalysts from IR and Catalytic Reactivity Studies,” Journal of Catalysis, Vol. 126, No. 2, 1990, pp. 591-599. doi:10.1016/0021-9517(90)90022-C

[38]   K. Na, T. Iizaki, T. Okuhara and M. Misono, “Molecular Design of Solid Acid Catalysts. Isomerization of n-Butane Catalyzed by Acidic Cesium Salts of 12-Tungstophosphoric Acid Combined with Platinum,” Journal of Molecular Catalysis, Vol. 115, No. 3, 1997, pp. 449-455. doi:10.1016/S1381-1169(96)00350-0

[39]   G. Koyano, K. Ueno and M. Misono, “Three Types of Acid Catalysis in Liquid Phase of Metal Salts of 12-Tungstophosphoric Acid, Mn+xH3?nxPW12O40,” Applied Catalysis A, Vol. 181, 1999, p. 267.

[40]   A. Corma, A. Martinez and C. Martinez, “Acidic Cs+, NH4+, and K+ Salts of 12-Tungstophosphoric Acid as Solid Catalysts for Isobutane/2-butene Alkylation,” Journal of Catalysis, Vol. 164, No. 2, 1996, pp. 422-432. doi:10.1006/jcat.1996.0398