Mixing Efficiency in Solid-Liquid Reactions

Another proposal is that catalysis occurs primarily at the surface. This is not because the rate of reaction is significantly faster than the rate of diffusion, but because the pores of the catalyst become filled with one phase only, which prevents the influx of the other reactant [62], 

Water is a unique solvent because of its high polarity and ability to form a network of H-bonds. It is immiscible with many organic solvents and is therefore a suitable solvent for use in biphasic reactions in which catalysts are made preferentially soluble in the aqueous phase. Phase transfer catalysis allows the use of aqueous reagents with substrates that have low solubility in water. That water is abundant and totally non-toxic make it the perfect clean solvent, provided that solubility issues can be overcome, and it is in use as a solvent on an industrial scale for polymerization, hydroformylation, and a range of organic chemistry involving PTC. These applications are discussed further in Chapters 7-11. 

Matlack A. S. Introduction to Green Chemistry, Marcel Dekker, New York, 2001. 

Vonnegut K. Cat s Cradle, Holt, Rinehart Winston, New York, 1963. 

Lancaster M. Green Chemistry An Introductory Text, Royal Society of Chemistry, Cambridge, 2002. 

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