The Improvement of Dehydriding the Kinetics of NaMgH3 Hydride via Doping with Carbon Nanomaterials

Abstract

NaMgH3 perovskite hydride and NaMgH3–carbon nanomaterials (NH-CM) composites were prepared via the reactive ball-milling method. To investigate the catalytic effect of CM on the dehydriding kinetic properties of NaMgH3 hydride, multiwall carbon nanotubes (MWCNTs) and graphene oxide (GO) were used as catalytic additives. It was found that dehydriding temperatures and activation energies (ΔE1 and ΔE2) for two dehydrogenation steps of NaMgH3 hydride can be greatly reduced with a 5 wt. % CM addition. The NH–2.5M–2.5G composite presents better dehydriding kinetics, a lower dehydriding temperature, and a higher hydrogen-desorbed amount (3.64 wt. %, 638 K). ΔE1 and ΔE2 can be reduced by about 67 kJ/mol and 30 kJ/mol, respectively. The results suggest that the combination of MWCNTs and GO is a better catalyst as compared to MWCNTs or GO alone.

Keywords

• NaMgH3 hydride
• doping
• carbon nanomaterial (CM) composite
• catalytic effect
• dehydriding kinetics