Investigation of the hydriding kinetic mechanism in the MgH2/Cr2O3-nanocomposite

A kinetic analysis was done in the nano-MgH2 and MgH2/MexOy-nanocomposite (MexOy=V2O5, Cr2O3 and Fe3O4) using a new kinetic model proposed recently in our group. The summarized data of hydriding rate are very well fitted using the new model, and it indicates that the rate-controlling step is the hydrogen diffusion through the hydride phase. Compared with the characteristic absorption time of these nano-MgH2 and MgH2/MexOy-nanocomposite, the difference in the kinetic property was investigated in an explicit analytic form and the order of reaction rate and the optimal amount of oxide catalyst Cr2O3 can be determined exactly. These facts support that our model is reasonable in the nano-MgH2 and MgH2/MexOy-nanocomposite system.