Standard state of adsorbate

The molar work done for moving the sorbate molecules from the ambient gas phase to the standard state of the adsorbed phase is defined as adsorption potential, A, by the Polanyi theory. The standard state of adsorbate in the adsorbed phase is a saturated liquid for the adsorption at... 

Sueeessful examples of the characteristie plot were presented by Dubinin and reproduced in Ruthven s book [73] however, problems arise when apphed to supercritical adsorption. Firstly, evaluation of adsorption potential is questionable because a saturated hquid cannot stand for the standard state of adsorbate at above-critical temperatures, and the adsorption potential cannot be properly calculated. Second, Eq. (39) cannot be evaluated because the absolute amount adsorbed, n and the adsorbed phase molar volume, V , are also questionable for supercritical adsorption. Although empirical assumptions, as summarized by Agarwal and Schwarz [55], have been made to tackle the problem, these assumptions lack support either experimentally or theoretically. 

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