Boron Doped <scp> Ti ₂ CrV </scp> Alloy as Room Temperature Reversible Solid State Hydrogen Storage Media

ABSTRACT Effect of boron doping on the structure and hydrogenation‐dehydrogenation characteristics of Ti 2 CrV alloy has been investigated in detail. The alloys were prepared by arc melting method and were characterized using techniques such as XRD, SEM and EDX. With boron incorporation, the plateau pressure of hydrogen absorption increases with a decrease in enthalpy value, confirming destabilization of the hydride. The alloy, Ti 1.9 CrVB 0.1 , shows a maximum total hydrogen absorption capacity of 3.8 wt%, under ambient conditions with enthalpy and entropy of hydrogenation reactions, −48 kJmol −1 and 112 Jmol −1 K −1 , respectively. With further increase in B addition in the alloy, the hydrogen absorption capacity decreases to 3.5 wt% at room temperature. As prepared alloys exist in BCC structure which phase transforms into FCC structure up on hydrogenation. In situ hydrogen desorption temperature is found to decrease with an increase in B concentration. Around 30°C decrease in hydrogen desorption temperature was observed for Ti 1.9 CrVB 0.1 alloy compared to parent Ti 2 CrV alloy, confirming the improved dehydrogenation properties upon B addition. Compared to the parent alloy, Ti 2 CrV, the hydrogen absorption rate of Ti 1.9 CrVB 0.1 alloy improved significantly with an increase in the number of hydrogenation/dehydrogenation cycles due to the pulverization of the alloy. Studies confirmed that a small amount of B addition, (i.e., Ti 1.9 CrVB 0.1 alloy) leads to better de‐hydrogenation behavior, higher hydrogen absorption kinetics and improved cyclic stability compared to the parent Ti 2 CrV alloy.