The Random Heterogeneous Model of Adsorption

Hill developed a canonical ensemble approach to investigate the case of a random distribution of adsorption energies. He assumed that only interactions between adsorbed molecules on nearest-neighbour sites needed to be accounted for and developed an equation for the partition function  

The isotherm equation of Hill may be written in a more general form  

The question now arises as to whether the distribution derived by inverting equation (106) wUl be significantly different from that distribution evaluated assuming the patchwise model, i.e. can the two models be differentiated by analysing isotherm data It is possible that both models will yield equally valid distributions leaving no criterion on which to choose between them. This has indeed been the case found by Rudzinski et when the condensation 

Another approach has been taken by Steele and Pierotti and Thomas. They use the gas-solid virial expansion, a general theory which is not restricted to localized adsorption Pierotti and Thomas included corrections for the 

A recent study that adopts the associated adsorbate model of Berezin and Kiselev may prove particularly useful in elucidating heterogeneity topK l-ogy. In their theoretical treatise, Jaroniec and Borowko assumed a dual adsorbent surface and the possibility of double associates. Thus by formulating quasi-chemical reactions  

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