Ti–V–Mn based metal hydrides for hydrogen compression applications

Highlights: • Ti–V–Mn based alloys were investigated as V was substituted for Nb, Cr, Mo and Ta. • The produced alloys were found to possess C14 Laves, BCC and FCC phases. • <0.2 Nb substituted for V led to small hysteresis and high dissociation pressures. • Ti_0.5–V_0.45–Nb_0.05–Mn is a suitable alloy to be used in a metal hydride compressor. - Abstract: Ti–V–Mn based alloys, consisting mainly of the hexagonal C14 Laves and BCC phases, with nominal compositions of Ti_0.5V_0.4TM_0.1Mn, where TM = Nb, Cr, Mo, Ta and Ti_0.5V_0.5−xNb_xMn, where x = 0.05 and 0.2, were synthesised by arc melting. It was found that small amounts of Nb substituted for V (x = 0.05 and 0.1) resulted in smaller hysteresis between absorption and desorption as well as higher hydrogen dissociation pressures, compared to Ti_0.5V_0.5Mn. These findings show that Ti_0.5–V_0.45–Nb_0.05–Mn is a suitable alloy to be used in a metal hydride compressor to deliver a pressure of 650 bar in the temperature range 303–473 K