Improvement effect of reversible solid solutions Mg2Ni(Cu)/Mg2Ni(Cu)H4 on hydrogen storage performance of MgH2

The hydrogen absorption/desorption kinetic properties of MgH2can be effectively enhanced by doping specific catalysts.In this work,MOFs-derived NiCu@C nanoparticles(～15 nm) with regular core-shell structure were successfully prepared and introduced into MgH2(denoted as MgH2-NiCu@C).The onset and peak temperatures of hydrogen desorption of MgH2-11 wt.% NiCu@C are 175.0℃ and282.2℃,respectively.The apparent activation energy of dehydrogenated reaction is 77.2±4.5 kJ/mol for MgH2-11 wt.% NiCu@C,which is lower than half of that of the as-milled MgH2.Moreover,MgH2-11 wt.% NiCu@C displays great cyclic stability.The strengthening "hydrogen pumping" effect of reversible solid solutions Mg2Ni(Cu)/Mg2Ni(Cu)H4is proposed to explain the remarkable improvement in hydrogen absorption/desorption kinetic properties of MgH2.This work offers a novel perspective for the design of bimetallic nanoparticles and beyond for application in hydrogen storage and other energy related fields.