1 research outputs found
MgH2 nanoparticles confined in reduced graphene oxide pillared with organosilica: a novel type of hydrogen storage material
Hydrogen is a promising energy carrier that can push forward the energy
transition because of its high energy density (142 MJ kg-1), variety of
potential sources, low weight and low environmental impact, but its storage for
automotive applications remains a formidable challenge. MgH2, with its high
gravimetric and volumetric density, presents a compelling platform for hydrogen
storage; however, its utilization is hindered by the sluggish kinetics of
hydrogen uptake/release and high temperature operation. Herein we show that a
novel layered heterostructure of reduced graphene oxide and organosilica with
high specific surface area and narrow pore size distribution can serve as a
scaffold to host MgH2 nanoparticles with a narrow diameter distribution around
~2.5 nm and superior hydrogen storage properties to bulk MgH2. Desorption
studies showed that hydrogen release starts at 50 {\deg}C, with a maximum at
348 {\deg}C and kinetics dependent on particle size. Reversibility tests
demonstrated that the dehydrogenation kinetics and re-hydrogenation capacity of
the system remains stable at 1.62 wt.% over four cycles at 200 {\deg}C. Our
results prove that MgH2 confinement in a nanoporous scaffold is an efficient
way to constrain the size of the hydride particles, avoid aggregation and
improve kinetics for hydrogen release and recharging