Modification research on the hydrogen storage performance of bimetallic
oxide Zn2Ti3O8 on MgH2
Abstract
This study successfully synthesized lamellar Zn2Ti3O8, TiO2, and
rod-shaped ZnO catalysts through hydrothermal and calcination methods,
comparing the catalytic performance of the three catalysts on MgH2.
Notably, Zn2Ti3O8 demonstrated significant synergistic enhancement in
the dehydrogenation temperature and desorption kinetics of MgH2.
Experimental results revealed that the MgH2 + 12 wt% Zn2Ti3O8 composite
material commenced dehydrogenation at approximately 185 °C, around 160
°C lower than pure MgH2. Furthermore, at 325 °C, MgH2 release d only
3.06 wt% H2 within 20 min, whereas the Zn2Ti3O8 doped composite system
achieved the same hydrogen release at 225 °C within 7 min. After
complete dehydrogenation, the MgH2 + 12 wt% Zn2Ti3O8 composite
material-initiated hydrogen absorption at 40 °C and absorbed
approximately 6.05 wt% H2 within 60 min at 200 °C. The activation
energies for hydrogen absorption and desorption of the composite
material decreased by 22.25 kJ·mol-1 and 44.67 kJ·mol-1, respectively,
compared to pure MgH2. Cycling experiments demonstrated that after 20
cycles, the MgH2 + 12wt% Zn2Ti3O8 composite material maintained
excellent cyclic stability, with hydrogen storage capacity still
exceeding 95%. Hence, this composite material exhibits outstanding
catalytic and hydrogen storage performance, holding potential
application value in enhancing hydrogen release rates and reducing
activation energy.