ChemInform Abstract: Advantages and Disadvantages of Zeolites as Catalysts in Organic Chemistry

Abstract

Abstract Like conventional solid catalysts, zeolites offer numerous advantages over liquid catalysts: less or no corrosion, no waste or disposal problems, high thermostability, easy set up of continuous processes, etc. Zeolites also have definite advantages and some disadvantages over conventional solid catalysts in a certain number of applications. Both are discussed in terms of the adjustment of the acidity and basicity, structural effects, concentration and adsorption effects, coke formation and deactivation. Actually, the main advantages of zeolites over conventional catalysts are due to the great acid strength they can have and to their great adaptability to practically all types of catalysis. Numerous potential applications of zeolites have been found in the synthesis of chemicals. The main limitations are (i) the great sensitivity of zeolites to deactivation by irreversible adsorption or steric blockage of heavy secondary products and (ii) the impossibility of using their microporosity for the synthesis of bulky molecules. Because of the greater polarity of functional compounds, it is more difficult to exploit the shape selectivity of zeolites for their reactions than in the case of hydrocarbons.