Synthesis of superacid catalysts SO4 2-/ZrO2(Pt) and WOx/ZrO2(Pt) for isomerization of n-alkanes

V. V. Brei; J. Fraissard; N. N. Levchuk; A. V. Melezhyk; K. I. Patrylak

V. V. Brei Інститут хімії поверхні НАН України
J. Fraissard Universite Pierre et Marie Curie
N. N. Levchuk Institute of Bioorganic and Petroleum Chemistry of National Academy of Sciences
A. V. Melezhyk Інститут хімії поверхні НАН України
K. I. Patrylak Institute of Bioorganic and Petroleum Chemistry of National Academy of Sciences

Анотація

Research has been conducted into the influence of the conditions of synthesis of SO₄^2-/ZrO₂ and WO₃/ZrO₂ systems and of doping of such systems with oxides of silicon and aluminium on their catalytic activity in n-hexane isomerization. An improved procedure for co-precipitation is used to synthezise superacid catalysts that exhibit high activity: the yield of branched isomers at 520 - 540 К is 65 - 70% with a selectivity for i-C₆ of 70 - 94% and n-hexane conversion of the order of 80%; the content of the most valuable substance, namely 2,2-dimethylbutane, in the isomerization products is 17 - 21 wt.%. WO_x/ZrO₂(Pt) catalysts prove to be more stable than SO₄^2-/ZrO₂(Pt). Doping of WO₃/ZrO₂ systems with oxides of aluminium, silicon, and niobium decreases their isomerization activity.

Посилання

Patrylak K.I., Bobonych F.M., Voloshyna Yu.G., Levchuk M.M., Il’in V.G., Yakovenko O.M., Manza I.A., Tsupryk l.M Ukrainian mordenite-clinoptilolite rocks as a base for linear hexane isomerization catalyst //Appl. Catal. A. - 1998. - V. 174. - P. 187-198.

Mangnus P.J., Jacobs A. - in B. van Keulen (Ed.), Akzo Catalysts Symposium. Hydroprocessing, Akzo Chem. Div., Amersfort, Netherlands. - 1991. - P 163.

Hino M., Arata K. Synthesis of Solid Superacid Catalyst with Acid Strength of H_o<-16.04 Hi. Chem Soc., Chem. Commun. - 1980. - N18. - P 851-852.

Hino M., Arata K. Synthesis of Solid Superacid of Tungsten Oxide Supported on Zirconia and its Catalytic Action for Reactions of Butene and Pentane Hi. Chem Soc., Chem. Commun. - 1988. - N. 18,- P. 1259-1260.

Iglesia E., Soled S.L., Kramer G.M, Hi Catal. - 1993-V. 144, - P. 238.

Tatsumi T., Matsuhashi H., Arata K, A Study of the Preparation Procedure of Sulfated Zirconia Prepared from Zirconia Gel, The Effect of the pH of the Mother Solution on the Isomerization Activity of n-Pentane //Bull. Chem. Soc Japan. - 1996, - V. 69. - N. 5. - P, 1191-1194.

Avdeeva V., de Haan J.W., Janchen J., Lei G.D., Schunemar.n V., van de Ven L.J.M., Sachtler W M H., van Santen R.A. Acid Sites in Sulfated and Metal-Promoted Zirconium Dioxide Catalysts Hi. Catal. - 1995 - V. 151, - P. 364-372

Morterra C , Cerrato G., Pinna F., Signoretto M., Strukul G. On the Acid-Catalyzed Isomerization of Light Parraffins over a ZrO₂/SO₄ System: The Effect of Hydration Hi. Catal. - 1994.-V. 149. -N 1. -P. 181-188.

Ward D A , Ko E.I. One-Step Synthesis and Characterization of Zirconia-Sulfate Aerogels as Solid Superacids Hi Catal - 1994 - V 150 -N 1. - P. 18-33.

Lopez T., Navarrete J., Gomez R., Novaro O. , Figueras F., Armendariz H. Preparation of Sol-Gel Sulfated ZrO₂-SiO₂ and Characterization of its Surface Acidity //Appl. Catal. A - 1995. - V. 125. N. 2. - P. 217-232.

Navio J A., Colon G, Masfas M., Campelo J.M.. Romero A.A , Marinas JM Catalytic Properties of ZrO₂-SiO₂: Effects of Sulfation in the Cyclohexene Isomerization Reaction Hi. Catal. - 1996. - V. 161. - P. 605-613

Gonzalez M R., Kobe J.M., Fogash K.B., Dumesic J A, Promotion of n-Butane Isomerization Activity by Hydration of Sulfated Zirconia Hi. Catal. - 1996. - V. 160. - P 290-298.

Boyse R.A, Ko E.I. Crystallization Behaviour of Tungstate on Zirconia and its Relationship to Acidic Properties. I. Effect of Preparation Parameters Hi. Catal. -1997. - V. 171. -N. 1. - P. 191-207.

Santiesteban J.G., Vartuli J.C., Han S., Bastian R.D., Chang C.D. Influence of the Preparative Method on the Activity of Highly Acidic WO_x/ZrO and the Relative Acidity Compared with Zeolites//J. Catal. - 1997 - V. 168. - P. 431-441.

Iglesia E., Barton D.G., Biscardi J.A., Gines M.J.L., Soled S.L. Bifunctional pathways in catalysis by solid acids and bases //Catalysis Today. - 1997. -V. 38 - N 3. - P. 339-360.

Barton D.G., Soled S.L., Iglesia E. Solid Acid Catalysts Based on Supported Tungsten Oxides //Topics in Catalysis. - 1998. V. 6 - P. 87-99.

Scheithauer M., Cheung T.-K, Jentoff RE, Grasselli R K , Gates B.C., Knözinger H. Characterization of WО_x/ZrО₂ by Vibrational Spectroscopy and n-Pentane Isomerization Catalysis//J. Catal. - 1998. - V. 180. N l.-P. 1-13.

Ivanov A.V., Vasina T.V., Masloboishchikova O.V,, Khelkovskaya-Sergeeva E.G., Kustov L.M., Zoiten P. Investigation of Alkane Isomerization in Presence of Superacid Catalysts Based on SO₄/ZrO₄ //Kinetika i Kataliz. - 1998. - V. 39 N. 3. - P. 396-406.

Barton D.G., Shtein M., Wilson R.D., Soled S.L., Iglesia E. Structure and Electronic Properties of Solid Acids Based on Tungsten Oxide Hi. Phys. Chem. B. - 1999. - V. 103 - P. 630-640.

Corma A. Inorganic Solid Acids and their Use in Acid-Catalyzed Hydrocarbon Reactions //Chem. Rev. - 1995. - V. 95. - N 3. - P. - 559-614.

Tanabe K., Holderich W.F. Industrial Application of Solid Acid-Base Catalysts //Appl. Catal. A. - 1999. V. 181. - P. 399-434.

Mobil Oil Corp., US Patents 5,345,026 (1994); 5,382,731 (1995); 5,449,847 (1995); 5,516,954(1996); 5,563,310(1996); 5,608,133 (1997).

Tanabe K. Catalysts and catalytic processes. - Moscow: Mir, 1993. (In Russian).

Dushet J., Guillaume D., Monnier A., van Gestel J., Szabo G., Nascimento P., Decker S //J. Chem.Soc., Chem. Commun. - 1999. - P. 1819.