Preparation and properties of titania pillared clay

Titania pillared montmorillonite was prepared by the reaction of Na-montmorillonite with titania sols. The sols were prepared from titanium isopropoxide by hydrolysis followed by peptization with hydrochloric acid. The pillar heights are 13.5–17 A, and the BET surface areas are about 300 m2/g. The pillared structure is thermally stable above 500°C. The TiO2 content is about 50% on 800°C dry basis. The titania sol particles seem to be positively charged and taken up by the ion-exchange with the Na+ ions of the interlayer spaces. The X-ray diffraction patterns and the pore size distributions vary depending on the peptization conditions of the titania sols used. The adsorption isotherms for various vapors of different sizes such as benzene, xylenes and mesitylene fit the BET adsorpton equation, indicating that the pore sizes are large enough so as to allow the multilayer adsorption of the molecules. Acid strength distribution of the product heat-treated at 500°C was determined by the amine titration method. The distribution is comparable to that of a system SiO2-TiO2 with high acidity.

[1]  B. Theng.  The Chemistry of Clay-Organic Reactions , 2024 .

[2]  G. Brindley,et al.  High Surface Area Solids Obtained by Reaction of Montmorillonite with Zirconyl Chloride , 1979 .

[3]  M. Occelli.  New routes to the preparation of pillared montmorillonite catalysts , 1986 .

[4]  R. M. Barrer,et al.  Activation of montmorillonite by ion exchange and sorption complexes of tetra-alkyl ammonium montmorillonites , 1955 .

[5]  G. M. Muha,et al.  Structure of the Complex Ion in Aqueous Solutions of Zirconyl and Hafnyl Oxyhalides , 1960 .

[6]  M. Occelli.  Catalytic cracking with an interlayered clay. A two-dimensional molecular sieve , 1983 .

[7]  L. Gatineau,et al.  High-resolution solid-state aluminum-27 and silicon-29 nuclear magnetic resonance study of pillared clays , 1985 .

[8]  H. Benesi.  Acidity of Catalyst Surfaces. II. Amine Titration Using Hammett Indicators , 1957 .

[9]  T. Pinnavaia,et al.  Layer cross-linking in pillared clays , 1985 .

[10]  Jean-Maurice Cases,et al.  Studies of hydrolyzed aluminum chloride solutions. 1. Nature of aluminum species and composition of aqueous solutions , 1980 .

[11]  M. Koizumi,et al.  Role of interlayer cations in the formation of acrylonitrile-montmorillonite complexes , 1974 .

[12]  T. Matsuda,et al.  Disproportionation of 1,2,4-trimethylbenzene over montmorillonite pillared by aluminium oxide , 1984 .

[13]  G. Brindley,et al.  Hydroxy-Nickel Interlayering in Montmorillonite by Titration Method , 1978 .

[14]  H. Hattori,et al.  The acidic properties of TiO2-SiO2 and its catalytic activities for the amination of phenol, the hydration of ethylene and the isomerization of butene , 1974 .

[15]  R. Burch,et al.  Zr-containing pillared interlayer clays. Part III. Influence of method of preparation on the thermal and hydrothermal stability , 1985 .

[16]  M. Occelli,et al.  Physicochemical Properties of Montmorillonite Interlayered with Cationic Oxyaluminum Pillars , 1983 .

[17]  T. Pinnavaia,et al.  On the pillaring and delamination of smectite clay catalysts by polyoxo cations of aluminum , 1984 .

[18]  M. Hattori,et al.  High surface area solids obtained by intercalation of iron oxide pillars in montmorillonite , 1984 .

[19]  S. J. Gregg,et al.  Adsorption Surface Area and Porosity , 1967 .

[20]  J. Kitagawa,et al.  Acidic properties of Binary Metal Oxides , 1973 .

[21]  T. Pinnavaia,et al.  Intercalated Clay Catalysts , 1983, Science.

[22]  T. Pinnavaia,et al.  New chromia pillared clay catalysts , 1985 .