Vanadium phosphorous oxide (VPO) is traditionally manufactured from solid vanadium oxides by synthesizing VOHPO 4？0.5H 2O (the precursor) followed by in situ activation to produce (VO) 2P 2O 7 (the active phase). This paper discusses an alternative synthesis method based on sol-gel techniques. Vanadium (V) triisopropoxide oxide was reacted with ortho-phosphoric acid in an aprotic solvent. The products were dried at high pressure in an autoclave with a controlled excess of solvent. This procedure produced a gel of VOPO 4 with interlayer entrapped molecules. The surface area of the obtained materials was between 50 and 120 m 2/g. Alcohol produced by the alkoxide hydrolysis reduced the vanadium during the drying step, thus VOPO 4 was converted to the precursor. This procedure yielded non-agglomerated platelets, which were dehydrated and evaluated in a butane-air mixture. Catalysts were significantly more selective than the traditionally prepared materials with similar intrinsic activity. It is suggested that the small crystallite size obtained increased their selectivity towards maleic anhydride.
References
[1]
Hodnett, B.K. Vanadium-Phosphorous Oxide Catalysts for the Selective Oxidation of C-4 Hydrocarbons to Maleic-Anhydride. Catal. Rev. Sci. Eng. 1985, 27, 373–424, doi:10.1080/01614948508064740.
[2]
Centi, G.; Cavani, F.; Trifiro, F. Selective Oxidation by Heterogeneous Catalysis; Kluwer Academic/Plenum Publishers: New York, NY, USA, 2001; p. 143.
[3]
Hutchings, G.J. Vanadium phosphate: A new look at the active components of catalysts for the oxidation of butane to maleic anhydride. Mater. Chem. 2004, 14, 3385–3395, doi:10.1039/b404610m.
[4]
Ballarini, N.; Cavani, F.; Cortelli, C.; Ligi, S.; Pierelli, F.; Trifiro, F.; Fumagalli, C.; Mazzoni, G.; Monti, T. VPO catalyst for n-butane oxidation to maleic anhydride: A goal achieved, or a still open challenge? Topics Catal. 2006, 38, 147–156.
Higgins, R.; Hutchings, G.J. To Imperial Chemical Industries Limited. US Patent 4 317 777, 2 March 1982.
[7]
Kamiya, Y.; Ueki, S.; Hiyoshi, N.; Yamamoto, N.; Okuhara, T. Preparation of catalyst precursors for selective oxidation of n-butane by exfoliation-reduction of VOPO4·2H2O) in primary alcohol. Catal. Today 2003, 78, 281–290.
[8]
Kamiya, Y.; Imai, H.; Okohura, T. Selective Oxidation of n-Butane over Highly Crystalline Vanadyl Pyrophosphate Catalyst Synthesized by Intercalation-exfoliation-reduction of Layered Vanadyl Phosphate Dihydrate. J. Jpn. Petrol. Inst. 2009, 52, 81–89, doi:10.1627/jpi.52.81.
[9]
Carreon, M.A.; Guliants, V.V.; Pierelli, F.; Cavani, F. Ordered mesostructured mixed metal oxides: microporous VPO phases for n-butane oxidation to maleic anhydride. Cataly. Lett. 2004, 92, 11–16, doi:10.1023/B:CATL.0000011088.73708.4d.
Rownaghi, A.A.; Taufig-Yup, Y.H. Novel Synthesis Technique for Preparation of Ultrahigh-Crystalline Vanadyl Pyrophosphate as a Highly Selective Catalyst for n-Butane Oxidation. Ind. Eng. Chem. Res. 2010, 49, 2135–2143.
[12]
Shpeizer, B.G.; Ouyang, X.; Heising, J.M.; Clearfield, A. Synthesis and crystal structure of a new vanadyl phosphate [H-0.6(VO)3(PO4)(3)(H2O)(3)]·4H(2)O and its conversion to porous products. Chem. Mater. 2001, 13, 2288–2296, doi:10.1021/cm0008821.
[13]
Centi, G.; Trifiro, F.; Ebner, J.R.; Franchetti, V.M. Mechanistic Aspects of Maleic-Anhydride Synthesis from C4-hydrocarbons over Phosphorus Vanadium-Oxide. Chem. Rev. 1988, 88, 55–80.
[14]
Horowitz, H.S.; Blackstone, C.M.; Sleight, A.W.; Teufer, G. V-P-O Catalysts for Oxidation of Butane to Maleic Anhydride–Influence of (VO)2H4P2O9 Precursor Morphology on Catalytic Properties. Appl. Catal. 1988, 38, 193–210, doi:10.1016/S0166-9834(00)82825-0.
[15]
Bordes, E. Crystallochemistry of V-P-O Phases and Application to Catalysis. Catal. Today 1987, 1, 499–526, doi:10.1016/0920-5861(87)85003-4.
[16]
Kamiya, Y.; Hiyoshi, N.; Ryumon, N.; Okuhara, T. Microstructures of V-P-O catalysts derived from VOHPO4 center dot 0.5H(2)O of different crystallite sizes. J. Mol. Catal. A 2004, 220, 103–112, doi:10.1016/j.molcata.2004.03.054.
[17]
Hiyoshi, N.; Yamamoto, N.; Ryumon, N.; Kamiya, Y.; Okuhara, T. Selective oxidation of n-butane in the presence of vanadyl pyrophosphates synthesized by intercalation–exfoliation–reduction of layered VOPO4·2H2O in 2-butanol. J. Catal. 2004, 221, 225.
[18]
Kamiya, Y.; Ryumon, N.; Imai, H.; Okuhara, T. Nano-sized crystallites of vanadyl pyrophosphate as a highly selective catalyst for n-butane oxidation. Catal. Lett. 2006, 111, 159–163, doi:10.1007/s10562-006-0140-9.
[19]
Ryumon, N.; Imai, H.; Kamiya, Y.; Okuhara, T. Effect of water vapor on the transformation of VOHPO4·0.5H(2)O into (VO)(2)P2O7. Appl. Catal. A 2006, 297, 73–80, doi:10.1016/j.apcata.2005.08.040.
[20]
Yan, C.; Sun, L.; Cheng, F. Handbook of Nanophase and Nanostructured Materials; Wang, Z.L., Li, Y., Zhang, Z., Eds.; Kluwer Academic/Plenum Publishers: New York, NY, USA, 2003; Volume 1, p. 72.
[21]
nnaciri, S.A.; Bardoux, P. Solution Synthesis of Vanadium and Titanium Phosphates. Mater. Sci. Forum 1994, 152–153, 331–334.
[22]
Farrusseng, D.; Julbe, A.; Lopez, M.; Guizard, C. Investigation of sol-gel methods for the synthesis of VPO membrane materails adapted to the partial oxidation of n-butane. Catal. Today 2000, 56, 211–220.
[23]
R'kha, C.; Vandenborre, M.T.; Livage, J.; Prost, R.; Huard, E. Spectroscopic Study of Colloidal VOPO4. 2H2O. J. Solid State Chem. 1986, 63, 202–215.
[24]
Pierre, A.C. Introduction to Sol-Gel Processing; Kluwer Academic Publishers: Norwell, MA, USA, 1998; p. 242.
Griesel, L.; Bartley, J.K.; Wells, R.P.K.; Hutchings, G.J. Preparation of vanadium phosphate catalyst precursors using a high pressure method. Catal. Today 2005, 99, 131–136.
[27]
Dong, W.; Bartley, J.K.; Dummer, N.F.; Girgsdies, F.; Su, D.; Schloegl, R.; Volta, J.; Hutchings, G.J. Reaction of vanadium phosphates with alcohols at elevated temperature and pressure. J. Mater. Chem. 2005, 15, 3214–3220, doi:10.1039/b505586p.
[28]
Griesel, L.; Bartley, J.K.; Wells, R.P.K.; Hutchings, G.J. Preparation of vanadium phosphate catalysts from VOPO4·2H(2)O: Effect of VOPO4·2H(2)O preparation on catalyst preparation. J. Mol. Catal. A 2004, 220, 113–119, doi:10.1016/j.molcata.2004.02.027.
[29]
Taufiq-Yap, Y.H.; Hasbi, A.R.M.; Hussein, M.Z.; Hutchings, G.J.; Bartley, J.; Dummer, N. Synthesis of vanadium phosphate catalysts by hydrothermal method for selective oxidation of n-butane to maleic anhydride. Catal. Lett. 2006, 106, 177–181.
[30]
Yamamoto, N.; Hiyoshi, N.; Okuhara, T. Thin-layered sheets of VOHPO4·0.5H2O prepared from VOPO4·2H2O by intercalation-exfoliation-reduction in alcohol. Chem. Mater. 2002, 14, 3882–3888, doi:10.1021/cm020292y.
[31]
Johnson, J.W.; Jacobson, A.J.; Brody, J.F.; Rich, S.M. Coordination Intercalation Reactions of the Layered Compounds VOPO4 and VOASO4 with Pyridine. Inorg. Chem. 1982, 21, 3820–3825, doi:10.1021/ic00140a044.
Misawa, M. Effective Diameter of Molecules and Liquid-gas Critical Point. J. Chem. Phys. 1990, 93, 8401–8402, doi:10.1063/1.459275.
[34]
El Haskouri, J.; Cabrera, S.; Roca, M.; Alamo, J.; Beltran-Porter, A.; Beltran-Porter, D.; Marcos, M.D.; Amoros, P. Synthesis of a new mesostructured lamellar oxovanadium phosphate assembled through an (S+X-10) mechanism. Inorg. Chem. 1999, 38, 4243–4248.
[35]
Poling, B.E.; Prausnitz, J.M.; O’Connell, J.P. The Properties of Gases and Liquids; McGraw-Hill: New York, NY, USA, 2001; pp. A–50.
[36]
Ennaciri, S.A.; Malka, K.; Louis, C.; Barboux, P.; R'kha, C.; Livage, J. Sol-gel synthesis and catalytic properties of vanadium phosphates Bulk materials. Phosphorus Res. Bull. 2000, 11, 87–93.
[37]
Kuehl, R.O. Design of Experiments: Statistical Principles of Research Design and Analysis; Brooks/Cole: Pacific Grove, CA, USA, 2000; p. 94.
[38]
Amoros, P.; Ibanez, R.; Martinez-Tamayo, E.; Beltran-Porter, A.; Beltran-Porter, D.; Villeneuve, G. New Vandayl Hydrogenphosphate Hydrates—Electronic-Spectra of the VO2+ Ion in the VO(HxPO4)x·yH2O Sysetem. Mater. Res. Bull. 1989, 24, 1347–1360, doi:10.1016/0025-5408(89)90140-2.
[39]
Busca, G.; Cavani, F.; Centi, G.; Trifiro, F. Natura and mechanism of formation of vanadyl pyrophosphate–active phase in normal-butane selective oxidation. J. Catal. 1986, 99, 400–414, doi:10.1016/0021-9517(86)90365-9.
[40]
Albonetti, S.; Cavani, F.; Ligi, S.; Pierelli, F.; Trifiro, F.; Ghelfi, F.; Mazzoni, G. The effect of glycols in the organic preparation of V/P mixed oxide, catalyst for the oxidation of n-butane to maleic anhydride. Studies Surface Sci. Catal. 2002, 143, 963–973.
[41]
Utamapanya, S.; Klabunde, K.J.; Schlup, J.R. Nanoscale metal-oxide particle clusters as chemical reagents—synthesis and properties of ultrahigh surface-area magnesium-hydroxide and magnesium-oxide. Chem. Mater. 1991, 3, 175–181, doi:10.1021/cm00013a036.
[42]
Nakamura, M.; Kawai, K.; Fujiwara, Y. Structure and Activity of Vanadyl Phosphate Catalysts. J. Catal. 1974, 34, 345–355.
