Skip to main content

Enhanced hydrogen storage properties of NaAlH4 co-catalysed with niobium fluoride and single-walled carbon nanotubes

Journal Article


Download full-text (Open Access)

Abstract


  • The effects of single-walled carbon nanotubes (SWCNTs) as a co-catalyst with NbF5 on the dehydrogenation and hydrogenation kinetics of NaAlH4 were investigated by X-ray diffraction, Fourier transform infrared spectroscopy, differential thermal analysis, temperature-programmed desorption, and isothermal hydrogen ab/desorption techniques. It has been revealed that there is a synergistic effect of SWCNTs and NbF5 on the de/rehydrogenation of NaAlH4, which improves the hydrogen de/absorption performance when compared to adding either SWCNTs or NbF5 alone. For example, the apparent activation energy for the first-step and the second-step dehydrogenation of the co-doped NaAlH4 sample is estimated to be 85.9 and 96.2 kJ mol(-1), respectively, using Kissinger's approach, which is lower than the pristine, SWCNT-, and NbF5 doped NaAlH4, respectively, indicating a reduced kinetic barrier. These results are attributed to the active Nb-containing species and the function of F anions, as well as the nanosized pores and high specific surface area of the SWCNTs, which facilitates the dissociation and recombination of hydrogen molecules on its surface and the atomic hydrogen diffusion along the grain boundaries and inside the grains, and decreases the segregation of bulk Al after the desorption. Hence, the combined catalytic mechanism is presented.

Publication Date


  • 2012

Citation


  • Mao, J., Guo, Z. & Liu, H. K. (2012). Enhanced hydrogen storage properties of NaAlH4 co-catalysed with niobium fluoride and single-walled carbon nanotubes. RSC Advances, 2 (4), 1569-1576.

Scopus Eid


  • 2-s2.0-84859138350

Ro Full-text Url


  • http://ro.uow.edu.au/cgi/viewcontent.cgi?article=1338&context=aiimpapers

Ro Metadata Url


  • http://ro.uow.edu.au/aiimpapers/339

Has Global Citation Frequency


Number Of Pages


  • 7

Start Page


  • 1569

End Page


  • 1576

Volume


  • 2

Issue


  • 4

Place Of Publication


  • United Kingdom

Abstract


  • The effects of single-walled carbon nanotubes (SWCNTs) as a co-catalyst with NbF5 on the dehydrogenation and hydrogenation kinetics of NaAlH4 were investigated by X-ray diffraction, Fourier transform infrared spectroscopy, differential thermal analysis, temperature-programmed desorption, and isothermal hydrogen ab/desorption techniques. It has been revealed that there is a synergistic effect of SWCNTs and NbF5 on the de/rehydrogenation of NaAlH4, which improves the hydrogen de/absorption performance when compared to adding either SWCNTs or NbF5 alone. For example, the apparent activation energy for the first-step and the second-step dehydrogenation of the co-doped NaAlH4 sample is estimated to be 85.9 and 96.2 kJ mol(-1), respectively, using Kissinger's approach, which is lower than the pristine, SWCNT-, and NbF5 doped NaAlH4, respectively, indicating a reduced kinetic barrier. These results are attributed to the active Nb-containing species and the function of F anions, as well as the nanosized pores and high specific surface area of the SWCNTs, which facilitates the dissociation and recombination of hydrogen molecules on its surface and the atomic hydrogen diffusion along the grain boundaries and inside the grains, and decreases the segregation of bulk Al after the desorption. Hence, the combined catalytic mechanism is presented.

Publication Date


  • 2012

Citation


  • Mao, J., Guo, Z. & Liu, H. K. (2012). Enhanced hydrogen storage properties of NaAlH4 co-catalysed with niobium fluoride and single-walled carbon nanotubes. RSC Advances, 2 (4), 1569-1576.

Scopus Eid


  • 2-s2.0-84859138350

Ro Full-text Url


  • http://ro.uow.edu.au/cgi/viewcontent.cgi?article=1338&context=aiimpapers

Ro Metadata Url


  • http://ro.uow.edu.au/aiimpapers/339

Has Global Citation Frequency


Number Of Pages


  • 7

Start Page


  • 1569

End Page


  • 1576

Volume


  • 2

Issue


  • 4

Place Of Publication


  • United Kingdom