Dispersion (materials science)
In materials science
is the fraction of atoms of a material exposed to the surface. In general:
- D = NS/NT
is the dispersion, NS
is the number of surface atoms and NT
is the total number of atoms of the material. Dispersion is an important concept in heterogeneous catalysis
, since only atoms that are exposed to the surface are able to play a role in catalytic surface reactions. Dispersion increases with decreasing crystallite size and approaches unity at a crystallite diameter of about 1 nm.