Abstract:The hydrogen absorption amount and kinetics of the slurry formed by suspending the MgNi alloy powder in liquid benzene were studied. It is discovered that hydrogen is absorbed by both the solid phase(alloy) and liquid phase(C₆H₆) and the hydrogen absorption rate varies with the temperature and the content of the Mg-Ni in the slurry. Most hydrogen absorption curves of the slurry fall into two regions, in which the mechanism of hydriding reaction in the slurry system is different. In the former region, the hydriding of the alloy proceeds with hydrogen diffusing through C₆H₆. The part in the second region is the outcome of the hydrogenation of C₆H₆. At 548K and under the hydrogen pressure of 4.5MPa the saturation capacity for the slurry of 80% C₆H₆(mass fraction)+20% MgNi(mass fraction) is 5.9% (mass fraction) hydrogen, which is 97% of the theoretic capacity of the slurry system. The hydride of the alloy MgNi, which is only the hydride of Mg₂Ni phase, Mg₂NiH₄, is an efficient catalyst for the hydrogenation of C₆H₆ into C₆H₁₂(C₆H₆+3H₂→C₆H₁₂) in the slurry system.

Key words:  MgNi alloy; slurry; benzene; cyclohexane; metal hydride