What is "chemisorption"

n. (context chemistry English) the process in which a substance is adsorbed on the surface of another by means of chemical rather than physical bonding

n. adsorption (especially when irreversible) by means of chemical instead of physical forces; "chemisorption of gaseous nitrogen on iron catalysts" [syn: chemosorption]

Chemisorption is a kind of adsorption which involves a chemical reaction between the surface and the adsorbate. New chemical bonds are generated at the adsorbant surface. Examples include macroscopic phenomena that can be very obvious, like corrosion, and subtler effects associated with heterogeneous catalysis. The strong interaction between the adsorbate and the substrate surface creates new types of electronic bonds.

In contrast with chemisorption is physisorption, which leaves the chemical species of the adsorbate and surface intact. It is conventionally accepted that the energetic threshold separating the binding energy of "physisorption" from that of "chemisorption" is about 0.5 eV per adsorbed species.

Due to specificity, the nature of chemisorption can greatly differ, depending on the chemical identity and the surface structure.