A catalytic mechanism investigation of TiF(3) on hydriding/dehydriding properties of Mg(85)Cu(5)Ni(10) alloy

In this research, Mg(85)Cu(5)Ni(10)–x wt% TiF(3) (x = 0, 2, 4, 6, 8) alloys were synthetized via ball milling and the catalytic mechanism of TiF(3) on hydrogenation and dehydrogenation of Mg(85)Cu(5)Ni(10) was studied. The microstructure, hydriding/dehydriding kinetics and thermodynamics of the alloys were discussed in detail. The TiF(3) catalyzed alloys have faster hydriding/dehydriding kinetics and lower thermodynamic stability. After hydrogen absorption and desorption, TiF(3) decomposes into TiH(2) and MgF(2). TiF(3), TiH(2) and MgF(2) promote to forming crystal defects, dislocations, grain boundaries and nanocrystals which are advantageous to speeding up the rate of hydrogen absorption and desorption. The dehydrogenation activation energy E(a)(de) and dehydrogenation enthalpy ΔH(de) are reduced to 81.462 from 116.767 kJ mol(−1) and 72.456 from 93.372 kJ mol(−1) respectively by 6 wt% TiF(3). An appropriate amount of TiF(3) can improve the hydriding/dehydriding kinetics and thermodynamics of Mg(85)Cu(5)Ni(10).