Physisorption

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Physisorption[1] or physical adsorption is a type of adsorption in which the adsorbate adheres to the surface only through Van der Waals (weak intermolecular) interactions, which are also responsible for the non-ideal behaviour of real gases. It is characterised by:[2]

  • Low ambient temperature, always under the critical temperature of the adsorbate;
  • Type of interaction: Intermolecular forces (van der Waals forces);
  • Low enthalpy: ΔH < 20 kJ/mol;
  • Adsorption takes place in multilayers;
  • Low activation energy.
  • The energy state of adsorbate is not altered.
  • Reversible.

[edit] Examples

N2 on iron at 80 K

[edit] See also

[edit] Notes and References

  1. ^ International Union of Pure and Applied Chemistry. "physisorption (physical adsorption)". Compendium of Chemical Terminology Internet edition.
  2. ^ IUPAC on properties of physisorption
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