Background: Since last two decades, there has been rigorous
efforts are going on to develop a hydrogen storage system for large-scale
application in fuel cells, mobiles and for automotive uses. The early
experimental data on hydrogen storage using CNTs contradicted theoretical
calculations, and there has been a large variation in the CNT hydrogen
storage capacity reported by various research groups. In present work, a
comparative study on hydrogen storage and release characteristics of bare as
well as three transition metals viz. Ni, Cu & Fe nanoparticles decorated
MWCNT at ambient temperature i.e. 298K and pressure range of 9-16 atm has
Methods: Synthesis, characterization and hydrogen adsorption-desorption
behavior of bare as well as transition metal (Ni, Cu and Fe) decorated
multiwalled carbon nanotubes has been studied systematically.
Results: The maximum hydrogen storage capacities of finely dispersed Ni, Cu,
and agglomerated Fe decorated and bare multiwalled carbon nanotubes measured
at 298K were 0.812 wt% (at 15.85 atm), 2.59 wt% (at 12.64 atm), 0.909 wt %
(at 15.45atm) and 0.654 wt% (at 12.84 atm) respectively. A mechanism
invoking metal nanoparticle mediated dissociation of hydrogen molecule and
its subsequent storage in carbon structure as well as defect sites has been
proposed to explain hydrogen storage and release behavior of metal-decorated
multiwalled carbon nanotubes.
Conclusion: The nature and morphology of metal nanoparticle has significant
role in controlling hydrogen adsorption-desorption characteristic of
decorated multiwalled carbon nanotubes.