THE INTERACTION OF ALKALINE-SOLUTIONS OF POTASSIUM BOROHYDRIDE WITH LANI(4.5)M(0.5) (M=NI, MN, CR, CO, FE, CU, AL) INTERMETALLIC COMPOUNDS

The behavior of LaNi(4.5)M(0.5) (M = Ni, Mn, Cr, Co, Fe, Cu, Al) inter metallic compounds (IMC) in alkaline solutions of KBH4 (0.1; 1.0; 4.0 mol L(-1) KOH) was investigated in the temperature range 298-318 K. Th e catalytic hydrolysis of KBH4 is zero order with respect to KBH4 and first order with respect to IMC. Activation energies of the catalytic hydrolysis of KBH4 in the presence of IMC are in the range of 60-65 kJ mol(-1). The rate of hydrolysis of KBH4 increases with the concentrat ion of the KOH solution. The hydrogenation of LaNi(4.5)M(0.5) in alkal ine solutions of KBH4 yields beta-hydride phases for M = Mn, Cr, Co, C u, Al and alpha-hydride phases for M = Ni, Fe.