A statistical physics approach to hydrogen sorption-desorption isotherms in LaNi4.3Fe0.7

• Published in: Journal of alloys and compounds 2024-08, Vol.996, p.174861, Article 174861
• Main Authors: Knani, Salah, Dotto, Guilherme Luiz, Dhaou, Mohamed Houcine, Ferreira Piazzi Fuhr, Ana Carolina, Pinheiro, Raphael Forgearini, Alshammari, Abdulmajeed, Mahmoud, Safwat A., Alenazi, Abdulaziz, Selmi, Ridha
• Format: Article
• Language: English
• Subjects: Hydrogen storage; Metal hydride; Sorption-desorption isotherms; Statistical physics modeling
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2024.174861

This study explores experimental hydrogen sorption and desorption isotherms on LaNi4.3Fe0.7 at four temperatures, employing different statistical physics models based on the grand canonical ensemble. The choice of the most appropriate model considered statistical parameters and physical analysis of the estimated parameters, culminating in selecting the monolayer model with two types of energies. The detailed analysis of these parameters provides an improved understanding of the process, highlighting the presence of hysteresis in the H2sorption and desorption in the metallic alloy. The sorption and desorption energies determined for this model vary between 82 and 109 kJmol−1, indicating a predominant chemical mechanism. Calculations of thermodynamic potentials suggest that the processes are exothermic and spontaneous. When comparing with other alloys of the same base, we observed that adding Fe presents similar trends in the model parameters, contributing to subtle improvements in the process. •H2 sorption and desorption isotherms on LaNi4.3Fe0.7 employing statistical physics.•The energies ranged from 82 to 109 kJ mol−1, indicating a chemical mechanism.•The simultaneous presence of Fe and Ni results in higher n1 and n2 values.•The Nasat values for each alloy tend to reduce with increasing temperature.