- Benefits of Heterogeneous Catalysis -
A catalyst is a substance that increases the rate of a chemical reaction without itself being changed in the process. In general, there are heterogeneous, homogeneous and biological catalysts. But running a reaction under heterogeneous catalytic conditions has several advantages compared to other catalytic processes:
- Avoids formation of inorganic salts
- Regenerable
- Non-toxic
- Easy to handle
- Safe to store, long life time
- Easy and inexpensive removal from reaction mixture by filtration or centrifugation
- Tolerates a wide range of temperatures and pressures
- Easy and safe disposal
Despite all this benefits, heterogeneous catalysts are not well known among organic chemists: e.g. the average chemists in an organic chemical laboratory uses zeolites only as molecular sieves for drying solvents.
This situation is slowly changing, also due to the commercial availibility of a wide variety of (functionalized) polymeric supports for uses in combinatorial chemistry.
- Types of Support -
A generally significant and sometimes critical variable is the choice of support. For a specific application, a large number of supports of widely different natures may be compared or the selection may be as narrow as different versions of the same material. Changing a support may completely alter the course of reaction or prevent catalysis.
Several types of heterogeneous catalysts are commercially available which can be categorized in several ways. One of the categorizations is based on their internal architecture:
- Amorphous Supports: Metal oxides (aluminas, silicas,..), carbon
- Layered Supports: Clays
- Microporous Supports: Zeolites (molecular sieves), (crosslinked) (functionalized) polymers
- Directory -
The web site "Heterogeneous Catalysts" is an excellent starting point for both a researcher new to the field as an expert who is looking for a intuitively organized web site about this subject.
Contents:
- Overview/Introductions in heterogeneous catalysis
- Classification of heterogeneous catalysts
(by internal architecture, chemical properties, nature of support)
- Characterization of heterogeneous catalysts
- Amorphous support
- Clays
- Zeolites
- Polymers
- Manufacturers and suppliers (25 listings)
- Journals about catalysis (16 listings)
- Recent secondary literature focused on synthetic organic chemistry (7 listings)
- Upcoming Meetings (4 listings)
- Research groups
- Societies (4 listings)
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