Ferrierite-type zeolites

L. Leherte, J.-M. Andre, E. G. Derouane, and D. P. Vercauteren, /. Chem. Soc., Faraday Trans., 87,1959 (1991). Self-Diffusion of Water into a Ferrierite-Type Zeolite by Molecular Dynamics Simulations. 

The adsorption of NO and CO has been used to characterize the properhes of Co in Co-exchanged zeoHtes [148-151]. NO is a selective probe for Co and CO is selective for Co species. Datka and coworkers used the combination of CO and NO adsorption IR to quantitahvely determine the concentration of Co as an oxide and the Co present as in exchange positions, oxide-like clusters, and cobalt oxide in a series of Co-exchanged ZSM-5 and ferrierite (PER) zeolites [151]. They established conditions under which the CO and NO would react selectively with the various types of sites and estabhshed absorphon coefficients for the quanhtative calculations. Differences in the distributions of the various forms of Co species were found to be dependent on both the structure and framework Si/Al of the zeolite. 

The zeolite-catalyzed alkoxylation of limonene (53, 54) and alpha-pinene (55, 56) over acid-treated mordenite, clinoptilolite and ferrierite as catalysts has already been reported in the literature. The best results were obtained for methoxylation of limonene in the presence of a clinoptilolite-type zeolite (60% yield). The alkoxylation of alpha-pinene with methanol in the presence of mordenite also achieved the highest yields of 66% for l-methyl-4-[alpha-methoxy-isopropyl]-l-cyclohexene. Syntheses of l-methyl-4-[alpha-alkoxy-isopropyl]-l-cyclohexenes via zeolite-catalyzed alkoxylation of other terpenes were reported in a review paper (57). 

The increase in isobutene selectivity with time-on-stream is a particular property of the ferrierite. This zeolite has two types of active sites the external sites (on the external surface of the zeolite crystallites) which are non-selective for skeletal isomerization and the internal sites (inside the zeolite pores) which are selective for this reaction (9). The changes observed on the selectivity have been associated with modifications of pore shapes ough coke deposition that favor reactions involving small molecules, such as -butene to isobutene isomerization (8). More recently, it has been reported that a bimolecular mechanism takes place at the non-selective acid sites, while a monomolecular mechanism occurs on the selective sites (10), the coke deposition being necessary in order to poison, block, and modify the non-shape selective acid sites. 

The microcalorimetric technique has also been applied to investigate the adsorption of acetonitrile, dimethylether, water, pyrrole and ammonia on ferrierite, a small-pore zeolite [58], This investigation showed that the results of the determination of the site-strength distribution are dependent on the basic strength of the probe, on the acidity and porosity of the acid solid, and on the adsorption temperature. A similar calorimetric investigation of the acidity of de-aluminated Y-type zeolites was performed using the same probes [59],... 

Marler B, Wang Y, Song J, Gies H. RUB-36, a new layer silicate with ferrierite-type layers which can be condensated to form a highly ordered CDO-type zeolite. In Book of Abstracts, 15th International Zeolite... 

In comparable reaction conditions as Pd +Cu +Y, Pd + and Cu2+ exchanged pentasil and ferrierite zeolites show a different type of activity [31]. The main products formed by propylene oxidation on these catalysts are acrolein and propionaldehyde below 120°C and 2-propanol above 120 C. Above 150°C consecutive oxidation of 2-propano1 to acetone is observed. The catalytic role of Pd and Cu in the 2-propanol synthesis is proposed to follow the Wacker concept. It is striking that when Pd + and Cu2+ are exchanged in 10-membered ring zeolites, oxidation of a primary carbon atoms seems possible, as acrolein and propionaldehyde are obtained from propylene. 

One notes the strong dependence of AEsteric as a function of the type of zeolite and also the large repulsive correction AEsteric for the zeolite with the narrow one-dimensional pore (ferrierite). We illustrate in the next section how the values of AEsteric can be used to assist kinetic analysis. 

Zeolites having mordenite-, ferrierite-, boggsite-, epistilbite-, and terranovaite-type framework... 

Since frequently the properties of ferrierites are compared with some synthetic materials (MFI, STT, MWW), which frameworks are different from FER-type, a short survey of their structural properties will be givea These properties will facilitate the conparative analysis, particularly connected with the location of exchanged ions in their lattice. The presentation will be limited only to synthetic conqxmnds that are mentioned along the chapter, particularly in correlation with ferrierite structural and catalytic properties. A definitive survey of these materials can be found in the Atlas of Zeolite Framework Types [07B4]. 

The chemical shift of zeolites as ferrierite [03B1] or IFR [OlVl] was shown to be independent on temperature for a given type of structure. This was consistent with the fact that Si-O-Si bond angles remained constant. 

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