Graphene-anchored Ni6MnO8 nanoparticles with steady catalytic action to accelerate the hydrogen storage kinetics of MgH2

Transition metal-based oxides have been proven to have a substantial catalytic influence on boosting the hydrogen sorption performance of MgH2. Herein, the catalytic action of Ni6MnO8@rGO nanocomposite in accelerating the hydrogen sorption properties of MgH2 was investigated. The MgH2 + 5 wt% Ni6MnO8@rGO composites began delivering H2 at 218 & DEG;C, with about 2.7 wt%, 5.4 wt%, and 6.6 wt% H2 released within 10 min at 265 & DEG;C, 275 & DEG;C, and 300 & DEG;C, respectively. For isothermal hydrogenation at 75 & DEG;C and 100 & DEG;C, the dehydrogenated MgH2 + 5 wt% Ni6MnO8@rGO sample could absorb 1.0 wt% and 3.3 wt% H2 in 30 min, respectively. Moreover, as compared to addition-free MgH2 , the de/rehy-drogenation activation energies for doped MgH2 composites were lowered to 115 & PLUSMN; 11 kJ/ mol and 38 & PLUSMN; 7 kJ/mol, and remarkable cyclic stability was reported after 20 cycles. Microstructure analysis revealed that the in-situ formed Mg2Ni/Mg2NiH4, Mn, MnO2, and reduced graphene oxide synergically enhanced the hydrogen de/absorption properties of the Mg/MgH2 system.& COPY; 2023 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Automated summary

Transition metal-based oxides have been proven to effectively enhance the hydrogen sorption performance of MgH2. In this study, the catalytic action of Ni6MnO8@rGO nanocomposite in accelerating the hydrogen sorption properties of MgH2 was investigated. The results showed that the MgH2 + 5 wt% Ni6MnO8@rGO composites released significant amounts of H2 at relatively low temperatures, and exhibited improved de/rehydrogenation stability and lower activation energies compared to undoped MgH2. Rating: 9/10