Abstract

Molecular sieves are inorganic materials that possess uniform pores with diameters in the micro-, meso-, or macrosize range. Heterogeneous catalysis and adsorption processes make extensive use of molecular sieves. The utility of these materials is manifested in their microstructures, which allow access to large internal surfaces and cavities that enhance catalytic and adsorptive capacity. The most technologically important molecular sieves are zeolites, which are high capacity, selective adsorbents capable of separating molecules based on the size and shape of the molecule relative to the size and geometry of the main apertures of the structures. They adsorb molecules with a selectivity that is not found in other solid adsorbents. Structure, manufacture, uses, properties, health and safety factors, and economic aspects are discussed.