Enhanced hydrogen sorption on modified MIL-101 with Pt/CMK-3 by hydrogen spillover effect

The effect of mesoporous carbon CMK-3 as a support on Pt catalytic activities, dissociation of hydrogen molecules and enhanced hydrogen absorption on modified MIL-101 at ambient temperature have been studied. The isotherms of these unmodified and modified samples have been investigated using volumetric method at 298 K and the pressure ranging from 1 to 20 bar. These modification with Pt (20 wt%)/CMK-3 and carbon bridge, the hydrogen uptake was almost twice that of pristine sample. The storage capacity of modified MIL-101 at 20 bar and 298 K was found to be 1.34 wt% which is significantly improved as compared to the pure MIL-101, it is because of the Pt nanoparticles were uniformly distributed on the mesopores of CMK-3 support. Therefore Pt catalytic activities in dissociation of hydrogen molecules are improved leading to significant changes in hydrogen sorption properties at room temperature. Also The obtained composite is characterized by various techniques such as powder X-ray diffractometry, scanning electron microscopy, porosimetry by nitrogen adsorption and desorption and hydrogen adsorption. (C) 2012 Elsevier B.V. All rights reserved.