Hydrogen sorption–desorption studies on ZrCo–hydrogen system

Abstract

The ZrCo–H2 system was investigated in this study owing to its importance as a suitable candidate material for storage, supply, and recovery of hydrogen isotopes. Desorption hydrogen pressure-composition isotherms were generated at six different temperatures in the range of 524–624 K. A van’t Hoff plot was constructed using the plateau pressure data of each pressure-composition isotherms and the thermodynamic parameters were calculated for the hydrogen desorption reaction of ZrCo hydride. The enthalpy and entropy change for the desorption of hydrogen were found to be 83.7 ± 3.9 kJ mol−1 H2 and 122 ± 4 J mol−1 H2 K−1, respectively. Hydrogen absorption kinetics of ZrCo–H2 system was studied at four different temperatures in the range of 544–603 K and the activation energy for the absorption of hydrogen by ZrCo was found to be 120 ± 5 kJ mol−1 H2 by fitting kinetic data into suitable kinetic model equation.