In-situ synchrotron X-ray diffraction study on the dehydrogenation behavior of NaAlH4 modified by multi-walled carbon nanotubes

The effect of multi-walled carbon nanotubes (MWCNTs) addition on the dehydrogenation behavior of NaAlH4 (sodium alanate) is investigated using high-pressure thermal gravimetric analysis (HPTGA) and in-situ synchrotron X-ray diffraction (in-situ synchrotron XRD) technique. The HPTGA results show that the addition of MWCNTs facilitates dehydrogenation of NaAlH4 by lowering the first-step dehydrogenation temperature to 80 °C. In-situ synchrotron XRD analysis demonstrates that the dehydrogenation pathway can be modified by the addition of MWCNTs which resulting in an enhanced hydrogen desorption rate and reduced desorption temperature.

► In-situ synchrotron X-ray diffraction analysis was used for dehydrogenation study of NaAlH4.
► The hydrogen desorption temperature of NaAlH4 can be lowered to 80 °C with MWCNTs addition.
► MWCNTs make a detour of the hydrogen desorption path of NaAlH4, and resulting Al4C3 formation.
► Activated carbon addition didn't show the same effect as MWCNTs on the dehydrogenation of NaAlH4.