Abstract
Statistical physics treatment is used to study the desorption of hydrogen on LaNi4.75Fe0.25, in order to obtain new physicochemical interpretations at the molecular level. Experimental desorption isotherms of hydrogen on LaNi4.75Fe0.25 are fitted at three temperatures (293 K, 303 K and 313 K), using a monolayer desorption model. Six parameters of the model are fitted, namely the number of molecules per site n(alpha) and n(beta), the receptor site densities N-alpha M and N-beta M, and the energetic parameters P-alpha and P-beta. The behaviors of these parameters are discussed in relationship with desorption process. A dynamic study of the alpha and beta phases in the desorption process was then carried out. Finally, the different thermodynamical potential functions are derived by statistical physics calculations from our adopted model. (C) 2015 Elsevier B.V. All rights reserved.