Encyclopedia of Membranes

Living Edition
| Editors: Enrico Drioli, Lidietta Giorno

Activity Coefficient

Living reference work entry
DOI: https://doi.org/10.1007/978-3-642-40872-4_1086-3

Chemical Thermodynamics

Depending on a specific area of fundamental science and technology, the term “activity” may have a different meaning. For example, in chemical thermodynamics, activity (a) is well known as a convenient variable to represent data, obtained experimentally or calculated theoretically, for the values of chemical potentials of components in real chemical solutions. For the \( i-th \)

This is a preview of subscription content, log in to check access.


  1. Bligaard T, Nørskov JK, Dahl S, Matthiesen J, Christensen CH, Sehested S (2004) The Brønsted–evans–polanyi relation and the volcano curve in heterogeneous catalysis. J Catal 224:206–217CrossRefGoogle Scholar
  2. Nørskov JK, Rossmeisl J, Logadottir A, Lindqvist L, Kitchin JR, Bligaard T, Jonsson H (2004) Origin of the overpotential for oxygen reduction at a fuel-cell cathode. J Phys Chem B 108:17886–17892CrossRefGoogle Scholar
  3. Zhang J (ed) (2008) PEM fuel cell electrocatalysts and catalyst layers. Springer, LondonGoogle Scholar

Further Reading

  1. Vielstich W, Lamm A, Gasteiger HA (eds) (2003) Handbook of fuel cells, vol 2, Electrocatalysis. Wiley, New YorkGoogle Scholar

Authors and Affiliations

  1. 1.DST HySA Infastructure Center of CompetenceNorth-West University, Faculty of EngineeringPotchefstroomSouth Africa