A situation in which molecules of
adsorbate are free to move about the surface.
Mobility of the
adsorbate will increase with temperature and mobile adsorption may be either localized or non-localized.
In localized mobile adsorption the
adsorbate spends most of the time on the adsorption sites but can migrate or be desorbed and
readsorbed elsewhere. In non-localized adsorption the
mobility is so great that a small fraction of the adsorbed species is on the
desorption sites and a large fraction at other positions on the surface.
Source:
PAC, 1976, 46, 71
(Manual of Symbols and Terminology for Physicochemical Quantities and Units - Appendix
II. Definitions, Terminology and Symbols in Colloid and Surface Chemistry. Part II:
Heterogeneous Catalysis)
on page 76