Designed synthesis, zeolite

As was shown here in some examples, the field of catalysis over zeolites, although marnre, is still very much alive. The chemists who work with the synthesis zeolites continue to be very creative, the focus now being placed on the synthesis of materials that can catalyze reactions other than the acidic ones and/or reactions of bulkier molecules, that is, synthesis of zeolites with larger micropores or with a very large external surface, such as nanosize and delaminated zeolites. New concepts related to the mode of action of zeolite catalysts continue to emerge, as shown here with the shape selectivity of the external surface. These concepts are particularly useful to scientifically design selective and stable catalysts. 

Chapter 1 is a general overview of zeolite, zeotype and mesoporous solids chemistry, including their design, synthesis and general catalytic properties. Chapter 2 deals with the problems and pitfalls that may occur in the applications of zeolites and other microporous and mesoporous solids to fine chemical synthesis. The remaining chapters deal with specific applications of these catalysts to fine chemical synthesis. 

K.D. Schmitt and GJ. Kennedy, Toward the Rational Design of Zeolite Synthesis - the Synthesis of Zeolite ZSM-18. Zeolites, 1994, 14, 635-642. 

At which extent the traditional definition of zeolites is still valid Are zeolite scientists still dealing with "crystalline aluminosilicates containing pores and cavities of molecular dimensions" [ 1 J, or did they create new materials original enough to render this time-honoured definition obsolete Indeed, the zeolite community has pushed afar the borders of his field of interest, as any healthy body of scientists has to do. Zeolite researchers presently deal with nanopores instead of micropores, self-assembly instead of synthesis, and they prepare periodical structures from any comer of the periodical table, well beyond the limits of the class of ordered silicates. The evolution of the subject (and of the vocabulary used to describe it) has been astounding and somewhat refreshing but the core of the activity of the zeolite scientist is still the same as it was when Barrer described the first documented synthetic zeolite in 1948 [2] to apply up-to-date characterisation techniques to the design, synthesis and application of periodical self-assembled objects. 

P-22 - The design of zeolites catalysts for the synthesis of orange blossom and apple fragrances... 

Haggin, J., Progress in design of zeolite synthesis, Chem. Eng. News, 13 September, 41-43 (1993). 

Toward Greener and Designed Synthesis of Zeolite Materials... 

SDAs are featured for their structure diversity and controllability to meet the objective of designed synthesis of zeolites with specific structures. Studies show that SDAs with proper shape, polarity, charges, and flexibility are the keys to achieve the design of novel zeolite structures [63]. Nowadays, many zeolite structures have been synthesized by using novel SDAs. Besides, hierarchical zeolites can be synthesized with bifunctional templates. Some representative works will be discussed later. 

Against the trend of using more complicated and expensive organic SDAs to produce new zeolite framework types, the CDM approach was initially proposed as a cheaper alternative for the designed synthesis of zeolites. The concept of CDM approach was first developed... 

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