Abstract
Using the grand canonical ensemble in statistical physics, a hydrogen absorption and desorption isotherms on LaNi4.85 Al0.15 alloy have been modeled by a monolayer model with two level of energy. The model has six physicochemical parameters which are deduced from the fitting of the isotherms at three temperatures T = 298 K, T = 303 K and T = 313 K. These parameters were used to better understand and compare between the absorption and desorption phenomena. A macroscopic study is achieved through thermodynamic functions as the internal energy, the entropy, the free enthalpy, the chemical potential, the enthalpy, and the free energy. We proved the coexistence of the α and β phases during absorption process.
Fig – Desorption isotherms for T = 313 K, T = 303 K and T = 298 K. [Display omitted]
•Application of a statistical physics model to interpret the hydrogen sorption on LaNi4.85Al0.15 alloy.•Derivation of thermodynamic potential functions to investigate the macroscopic properties of hydrogen sorption process.•The coexistence of the α and β phases during absorption process is proved.