Effect of PdCl2 catalyst on the hydrogenation properties and sorption kinetics of Mg

Abstract

Slow hydrogenation kinetics and high de/absorption temperature of Mg/MgH2 still a challenge in solid state hydrogen storage systems for industrial and automobile applications. The effect of PdCl2 on the hydrogenation properties including kinetics of Mg/MgH2 has been investigated in the present study. The nanocomposites of Mg and PdCl2 were prepared using Ball Mill method with different concentrations of PdCl2. The synthesized nanocomposites were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), pressure-composition-isotherm (PCI) and differential scanning calorimetry (DSC). The result indicates that the maximum hydrogen storage capacity were achieved 6.15 wt% for Mg-5 wt% PdCl2 nanocomposites, while milled Mg only absorb 3.417 wt% H2 at 300 °C. The desorption kinetics not so much improved with PdCl2 concentration. It is concluded that the onset temperature of Mg-PdCl2 nanocomposites shifted towards lower side than milled Mg using DSC analysis. The SEM and XRD patterns confirm the phase identity maintain during ball milling. The new phases of PdH0.778, MgCl2, Mg6Pd and various phases of MgH2 in MgH2-PdCl2 nanocomposites were confirmed on the basis of XRD analysis and reported data of the sample.