Micro- and mesoporous solids: From science to application

The concept of a porous solid might sound like a term of contradiction as solids are typically regarded as a dense and compact state of matter. Of course this is obviously not so, and zeolites are probably the most prominent representatives of such solids, known for already more than 250 years, and have been used in technical applications for more than 50 years in industry. 200 different structural types of zeolites have already been listed, with this number increasing each year. However, the pore sizes of zeolites are restricted to well below 1 nm (for faujasite), which in turn restricts the scope of the chemistry that is possible inside the pores, typically to the molecular level.