Abstract
Hydrogen uptake of pristine multi-walled carbon nanotubes is increased more than three-fold at 298 K and hydrogen pressure of 4.0 MPa, upon addition of hydrogen spillover catalyst manganese oxide, from 0.26 to 0.94 wt%. Simple and convenient in situ reduction method is used to prepare Mn-oxide/MWCNTs composite. XRD, FESEM, and TEM demonstrates nanostructural characterization of pristine MWCNTs and composite. TGA analysis of Mn-oxide/MWCNTs composites showed a single monotonous fall related to MWCNTs gasification. Enhancement of hydrogen storage capacity of composite is attributed to spillover mechanism owing to decoration of Mn-oxide nanoparticles on outer surface of MWCNTs. Hydrogen uptake follows monotonous dependence on hydrogen pressure. Oxide-MWCNTs composite not only shows high hydrogen storage capacity as compared to pristine, but also exhibit significant cyclic stability upon successive adsorption–desorption cycles.
[Display omitted] Preparation and hydrogen uptake study representation of metal-oxide/MWCNTs composite.
•Preparation of Mn-oxide/MWCNTs composites by in situ reduction method.•XRD, FESEM and TEM analysis demonstrates nanostructured characterization of samples.•Hydrogen uptake enhancement of composites is more than three times compared to pristine MWCNTs.•Enhancement of hydrogen uptake of composites is attributed to spillover mechanism.•Monotonous dependence on hydrogen pressure and cyclic stability upon successive adsorption-desorption cycles.