Enhancing hydrogen storage properties of MgH2 by core-shell CoNi@C

Introducing multicomponent nanoparticles can improve remarkably de/hydrogenation kinetic properties of MgH2. In this work, the original core-shell CoNi@C bimetallic nanoparticles were obtained via hydrothermal and calcination reduction technology. MgH2-8 wt% CoNi@C starts to dehydrogenate at 173 degrees C with the dehydrogenation capacity of 5.83 wt% within 1800 s at 275 degrees C. Moreover, the composite absorbs 4.83 wt% H-2 within 1800 s at 100 degrees C with prominent advantage at low temperature. The notable improvement of hydrogen storage properties of MgH2 is attributed to the reversible phase transitions of Mg2Co/Mg2CoH5 and Mg2Ni/Mg2NiH4, and the excellent thermal conductivity and confinement effect of the carbon shell. As a result, the apparent activation energy of dehydrogenation reaction reduces to 78.5 kJ/mol. This work extends the horizon of bimetallic nanoparticles with especial microstructure for enhancing the hydrogen storage properties of metal hydrides. (C) 2020 Elsevier B.V. All rights reserved.

Automated summary

Introducing multicomponent nanoparticles can significantly improve the de/hydrogenation kinetic properties of MgH2. The CoNi@C bimetallic nanoparticles show great potential in enhancing the hydrogen storage properties of MgH2, especially at low temperatures.