Investigation on platinum loaded multi-walled carbon nanotubes for hydrogen storage applications

Abstract

Molecular hydrogen uptake of modified carbon nanotubes is a prospect for efficient hydrogen storage in fuel cell vehicles. In this study, a simple and efficient method to decorate the surface of multi-walled carbon nanotubes (MWNT) with platinum nanoparticles is presented. To load the Pt nanoparticles, hexachloroplatinic acid (H2PtCl6·6H2O) is used as a precursor. Surface morphology of these Pt loaded MWNT is observed using Scanning and Transmission Electron Microscopy. Both samples are also characterized by X-Ray Diffraction. Thermal Gravimetric Analysis results indicate that both as purchased MWNT and Pt loaded MWNT have decomposition temperature higher than 500 °C in air. N2 adsorption experiments yields a BET area of the sample close to 500 m2/g. This MWNT/Pt sample was reduced in 10% of H2 in Ar, flowing at 900 °C in a tubular furnace for 1 h before hydrogen adsorption measurements. Hydrogen uptake of MWNT/Pt was measured at 2.5 MPa and 77 K. This hydrogen uptake isotherm is also compared with measurements at ambient temperature.