Hydrogen storage properties of Ti2FeV BCC solid solution

This paper deals with hydrogen storage properties of Ti-V based BCC solid solution incorporated with Fe. The alloy with composition Ti2FeV was prepared by arc melting method. X-ray diffraction (XRD) and energy dispersive X-ray analysis studies confirmed formation of solid solution phase with uniform composition and BCC structure. SEM studies revealed the formation of irregular shaped particles with size in the range of few microns up on hydrogenation of the parent alloy. The alloy shows maximum hydrogen storage capacity of 3.41 wt.% at 20 bar and 303 K and the thermodynamic parameters established near room temperature suitability of the alloy for solid state hydrogen storage applications. Hydrogenation kinetics is found to be quite fast and detailed kinetic analysis were done to underscore the hydrogenation mechanism. Activation energy during the initial stage of hydrogenation is found to be 30.8 kJ/mol. The value decreases to 14.4 kJ/mol for extended duration of hydrogenation, and this is explained based on difference in rate determining steps existing at different time scales. Extent of hydrogen absorption as a function of temperature and time for Ti2FeV alloy.