Hydrogen absorption properties of the slurry system composed of liquid C6H6 and F-treated Mg2Ni

The hydrogenation characteristics of the slurry composed of the NH4F solution treated Mg2Ni and liquid C6H6 were studied. The F-treatment results in a net-shaped MgF2 surface and higher nickel content in the sub-layer. It is found that the hydride of the NH4F treated alloy has a much higher activity for the hydrogenation of benzene. The catalytic activity for hydrogenation of the alloy depended strongly on the surface properties of the catalyst. At 483 K and under a hydrogen pressure of 4.0 MPa, the alloy absorbed hydrogen first, transformed into hydride and then the benzene was hydrogenated to cyclohexane with the hydride as the catalyst. The hydrogen absorption capacity of slurry system composed of 20 wt.% treated alloy and benzene reached similar to6.4 wt.% and the hydrogenation completed in similar to20 min. Results of X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) analysis on the crystal structure, surface composition and surface morphology of the untreated and treated alloy are presented and discussed. (C) 2002 Elsevier Science B.V. All rights reserved.