(717d) Hydrogen Sorption Properties of Pd-C60 and Ru-C60 Complex at Ambient Temperature

Pd-C60 and Ru-C60 complex was synthesized by incipient wetness impregnation technique with the metal acetylacetonates as precursors. Transmission electron microscopy (TEM) imaging of the complexes confirmed the particle type formation palladium on to C60 matrix unlike ruthenium where the metal deposition was close layer type. Raman spectra revealed the drastic decrease in peak intensity followed by disappearance of several bands indicating the distortion of the cage structure. The amorphous nature of the complex was revealed by the X-ray diffraction study. Hydrogen adsorption measurement at 300 bar pressure and 298K temperature indicated the enhancement of hydrogen uptake in the metal-fullerene complex compared to that of pristine one; 0.85 wt% and 0. 69 wt% by Pd-C60 and Ru-C60 respectively compared to 0.3 wt% by pure fullerene. The enhancement in hydrogen uptake can be attributed to several factors, including adsorption of molecular H2 in to defect sites, metallic hydride formation, spill-over of hydrogen and the bond formation with atomic hydrogen with different active sites of carbon of host fullerene. Sorption isotherms are all of type III which were modeled best by Freundlich (for Ru-C60) and modified Oswin equations (for Pd-C60 and pristine C60).