mikroporer

Mikroporer is a term used in materials science to describe porous solids that contain a network of pores with diameters of a few nanometers or smaller. In the IUPAC pore-size classification, micropores are defined as pores with diameters below 2 nanometers, distinct from mesopores (2–50 nm) and macropores (>50 nm). Materials described as mikroporer typically exhibit very high surface areas and strong adsorptive properties due to their small pore dimensions.

Examples of mikroporer materials include zeolites, activated carbons, and some metal–organic frameworks and covalent organic frameworks that possess dominant microporosity. The term can also be used for carbon nanotube–derived networks and silica gels with interconnected micropores. The microporosity can be intrinsic to the crystal structure or generated by templating and activation processes.

Key properties include exceptionally high surface area, selective adsorption of small molecules, and transport that is strongly influenced by pore size and shape. Synthesis methods vary: zeolites are typically formed by hydrothermal crystallization from silicate and aluminate precursors, activated carbons by carbonization and chemical activation, and MOFs/COFs by self-assembly of organic linkers with inorganic nodes. Activation and post-synthesis treatments can increase micropore volume and accessibility.

Applications of mikroporer materials span gas storage and separation, catalysis, and environmental remediation. Their ability to adsorb CO2, H2, or methane at low pressures makes them attractive for carbon capture and natural-gas upgrading. In catalysis, micropores provide high surface area and shape selectivity. Characterization relies on nitrogen adsorption–desorption isotherms at 77 K, BET surface area, and pore-size distributions derived from models such as Density Functional Theory.