Pillared Clays and Related Catalysts


Book Description

Since the first works introducing the aluminum intercalated clay family in the early 1970s, interest in the synthesis of pillared interlayered clays has increased tremendously, especially research into the properties and applications of new synthesis methods. The need for solids that could be used as cracking catalysts with larger pores than zeolitic materials has spurred the synthesis of new porous materials from clays. Pillared Clays and Related Catalysts reviews the properties and applications of pillared clays and other layered materials used as catalysts, focusing on: the acidity of pillared clays and the effect it has on catalytic performance the use of pillared clays as supports for catalytically active phases, and the use of the resulting solids in environmentally friendly reactions the applications of the selective reduction of NOx the comparison between the reactions of pillared clays and anionic clays.




Catalytic Cracking of Polypropylene and Polyethylene Using Zirconium/aluminium Oxide-pillared Clay


Book Description

Aluminium oxide-pillared clay was prepared by intercalation between ionic precursors and raw clay suspensions with any previous purification and homoionisation of clay prior to pillaring. The intercalated product was calcined at 500 degress celsius for 1h. And then was impregnated with various amounts of zirconium (from 0.0 to 5.0 wt%) by slurry method and calcined at 450 degress celsius for 4h. The basal spacing, the surface area, the aluminium contents and the vibrational of chemical bonds in different environments were determined by XRD, N[subscript 2] -BET, ICP-AES and IR respectively. The synthesized aluminium oxide-pillared clay had a basal spacing and surface area of 16.3 aungstrom and 189 m[superscript 2] g [superscript-1]. The basal spacings of zirconium doped aluminium oxide-pillared clays(zirconium/aluminium oxide-pillared clays) at 15.6 aungstrom were lower than aluminium oxide-pillared clay. Increasing amount of zirconium, the surface area decreased from 188 to 131 m [superscript 2] g [superscript -1]. When compared catalytic cracking reaction between two type of polymer observed that polyethylene more difficult than polypropylene. When aluminium oxide-pillared clay and zirconium/aluminium oxide-pillared clays were used as catalysts, the conversions of both polymers greatly increased compared to that in the absence of a catalyst. The cracking reaction was carried out in a semi-batch reactor with a mixture of catalyst and plastic at 350-450 degress celsius. The effects of reaction temperature, reaction time, type of catalyst and catalyst per plastic ratio were discussed. The activity and selectivity of catalysts modified by impregnation of zirconium were higher than the original clay catalyst. Gaseous and liquidous hydrocarbon products were analysed by GC. The optimal condition for PP cracking was reaction time of 1.0 h, reaction temperature of 380 degress celsius, 2.0wt%zirconium/aluminium oxide-pillared clay as a catalyst and 10.0 wt% catalyst per plastic ratio. The major components of gas fraction were C [subscript 5] + and C [subscript 3] (propene). Liquid fractions were in he range of C [subscript 7] to C [subscript 9] with the boiling point range compared to that of standard gasoline. The optimal condition for PE cracking was reaction time of 1.5 h, reaction temperature of 410 degress Celsius, 2.0 wt%zirconium/aluminium oxide-pillared clay and 10.0 % catalyst per plastic ratio. The major components of gas fractions were C [subscript 5+], C [subscript 4](n-butane), C [subscript 3] (propene), C [subscript 2] (ethane) and C [subscript 1] (methane). Liquid fractions were in he range of C [subscript 7] to C [subscript 10].




Clay Mineral Catalysis of Organic Reactions


Book Description

The book provides insight into the working of clays and clay minerals in speeding up a variety of organic reactions. Clay minerals are known to have a large propensity for taking up organic molecules and can catalyse numerous organic reactions due to fine particle size, extensive surface area, layer structure, and peculiar charge characteristics. They can be used as heterogeneous catalysts and catalyst carriers of organic reactions because they are non-corrosive, easy to separate from the reaction mixture, and reusable. Clays and clay minerals have an advantage over other solid acids as they are abundant, inexpensive, and non-polluting.




Pillared Clay Mineral Catalysts


Book Description

Samples of pillared interlayered clay mineral catalysts (PILCS) were prepared using montmorillonite as the clay mineral and Al13, Ga13, and GaAl12 as the pillaring species. The effect of adjusting the pH of the pillaring solution on the surface area and thermal stability of the resulting minerals was investigated. The catalysts were tested for their activity in cumene cracking and octane hydrocracking reactions. A computer program was written to assist in understanding the kinetic results obtained for the octane hydrocracking reaction.







Pillared Clays


Book Description







Fine Particle Clay Catalysts for Coal Liquefaction. Quarterly Technical Progress Report, May 9, 1992--August 8, 1992


Book Description

An investigation of new methods for the production of mixed pillared clay catalysts and clay-supported catalysts and determination of their catalytic activities were continued in this quarter. To demonstrate the reproducibility of the preparative method for high activity iron/alumina-pillared montmorillonite catalysts, a new batch of the catalyst was prepared and tested for hydrocracking activity with bibenzyl. This preparation gave conversion and product distribution similar to that reported previously. The mixed iron/alumina-pillared clay was also prepared using a pillaring solution that was aged for longer period of time. To determine the importance of the type of pillaring support in hydrocracking activity, iron/zirconia-pillared montmorillonite was prepared using the same technique as that for iron/alumina-pillared montmorillonite. The reaction of bibenzyl with the sulfided iron/zirconia-pillared catalyst gave a lower hydrocracking conversion than the iron/alumina-pillared catalyst. Addition of a second catalytic metal to the clay support was attempted to determine if a synergistic effect could improve liquefaction. Ferric nitrate and stannous chloride were added to the clay, but the resulting catalyst was relatively poor for hydrocracking and hydrogenation compared with ferric nitrate supported on the clay. New disposable iron catalysts with high acidity and surface area are desired for coal liquefaction. Synthetic iron aluminosilicates were prepared by methods similar to those used for the nickel-substituted synthetic mica montmorillonite (NiSMM) catalysts, which are very effective for hydrogenation and reforming of hydrocarbons. The iron aluminosilicate catalysts were tested for hydrocracking and hydrogenation of bibenzyl, naphthalene and pyrene. Pyrene hydrogenation was effectively catalyzed by the sulfided synthetic iron catalyst.