Effects of the preparative parameters of hydriding combustion synthesis on the properties of Mg–Ni–C as hydrogen storage material

Magnesium may be the most promising solid-state hydrogen storage material owing to its high storage capacity (7.6 wt%) and highest volumetric density (2 times of liquid H2). On the other hand, suffers from its sluggish absorption/desorption characteristics. In the present study, the simple/cost-effective hydriding combustion synthesis (HCS) was used to prepare highly-active Mg-based-samples. The preparative parameters of HCS were varied, and its effects on the micro-structural and hydrogen storage properties were determined. The results and its analysis showed that the simple HCS process possesses a multifaceted dependence on a range of experimental factors and affect the final product. The estimated dependence enabled us to explain the combined effect of individual experimental factors on the prepared samples. The Mg–Ni–C sample prepared at 610 °C with 6%wt-nano-Ni and 4 wt%-multi-walled-CNTs as reactants, resulted in sample with a surface area as high as 19.01 m2/g and a desorption capacity of 5.77 wt%, highlighting the promising characteristics of HCS to prepare highly-active Mg-based-materials.

► First time the effect of preparative parameters of hydriding combustion is reported. ► Easily HCSed product show multifaceted dependence on experimental factors. ► HCSed Mg–Ni–C alloys showed surface area as high as 19.01 m2/g. ► Highly active HCSed Mg–Ni–C alloy disrobed 5.77 wt. % of H2 in few minutes.