Effect of graphene templated fluorides of Ce and La on the de/rehydrogenation behavior of MgH2

The present study suggest that in contrast to stand alone additive (ie. CeF4 and LaF3), Gr templated additive (i.e. CeF4@Gr and LaF3@Gr) shows improved hydrogen sorption in MgH2. Lower desorption temperature (245 °C) and dual tuning effect, i.e. lowering of thermodynamic (62.77 kJ/mol H2: lower from 74 kJ/mol for pristine MgH2) and kinetics barrier (93.01 kJ/mol) has been observed for MgH2 ball milled with CeF4@Gr (MgH2:CeF4@Gr). Additionally, MgH2:CeF4@Gr shows good reversibility up to 24 cycles of de/rehydrogenation. The feasible working mechanism of CeF4@Gr as additive for MgH2 has been studied in detail with the help of Transmission Electron Microscope (TEM), Fourier Transform Infrared Spectroscopy (FTIR) and X-ray Diffraction characterizations (XRD).251