Spectroscopic study of hydrogen storage of Mg-Pd nanocomposite material

The hydrogen storage property of the composite of Mg and Pd nanoparticles (Mg NPs-Pd NPs) has been investigated by the QCM technique without the exposure to the air. The Mg NPs-Pd NPs can absorb the hydrogen under the room temperature and 760 Torr of H2 gas. However, the desorption of the hydrogen has not been observed under the vacuum condition. We have also studied the chemical state of the Mg NPs-Pd NPs by XPS and XAFS. The XPS spectra have shown the interfacial Mg-Pd alloy state between the Mg NPs and Pd NPs. The XAFS analyses have revealed that the MgH2 in the Mg NPs can not be dehydrogenated at the room temperature in spite of the high catalytic activity of Pd.