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Hier finden Sie wissenschaftliche Publikationen aus den FraunhoferInstituten. NonArrhenius form of the Henry adsorption on inhomogeneous substrates: The effect of frozen disorder
 Adsorption 23 (2017), Nr.78, S.923932 ISSN: 09295607 

 Englisch 
 Zeitschriftenaufsatz 
 Fraunhofer UMSICHT Oberhausen () 
 adsorption; adsorption energy; arrhenius law; disordered substrate; Henry constant 
Abstract
Usually, when considering submonolayer adsorption at different temperatures T, the logarithm of the Henry constant is represented as (Formula presented.) with some constant “heat of adsorption” U0 > 0. However, such Arrheniustype form has a clear base only for an ideal translationalinvariant crystal substrate. In more real situation, e.g. for a structurally disordered substrate, the “heat of adsorption” will be some random function of twodimensional coordinates characterized by some distribution function of its different values. Starting from general principles of the theory of Gaussian fluctuations, we show that the adsorption at the substrate with bulk inhomogeneous structure leads to expression (Formula presented.) with some fluctuation quantity Δ. A possibility to observe such “nonArrhenius” additive seems most favorable at rather low temperatures for substrates modeled by substitutional solid solutions. The theoretical predictions are illustrated by comparison with the experimental data obtained for some disordered adsorbents.