In situ formed ultrafine metallic Ni from nickel (II) acetylacetonate precursor to realize an exceptional hydrogen storage performance of MgH2Ni-EG nanocomposite

In Situ Formation of Mg2Ni on Magnesium Surface via Hydrogen Activation for Improving Hydrogen Sorption Performance

“…It illustrates the excellent activity of Mg 2 Ni for the dehydrogenation kinetics of MgH 2 . Moreover, the E a value of the hydrogenated Mg−5NiO is also lower than that of MgH 2 − NiO (119.7 kJ/mol H 2 ),30 Mg−NiF 2 (139.21 kJ/mol H 2 ),50 and MgH 2 −Ni-EG (114.7 kJ/mol H 2 ) 51. These results illustrate the excellent catalytic activity effect of Mg 2 Ni on the dehydrogenation kinetics of MgH 2 .According to the analysis mentioned above, a possible mechanism for improving the hydrogen sorption kinetics by in situ formed Mg 2 Ni is proposed.…”

Synergistic Effect of the Hydrogen Pump and Heterostructure Enables Superior Hydrogen Storage Performance of MgH2

“…34 Additionally, a significant number of phase interfaces exist within the Mg or MgH 2 matrix (Figures S9 and S10), encompassing interfaces between catalytic phases and the catalytic host, as well as interfaces among catalytic phases, which provide ample channels for the diffusion of hydrogen. 32,33 Furthermore, theoretical calculations were conducted to unravel the catalytic effect of different components in catalysts (Figure 7 and Table 1). The Mg−H bond length in pure MgH 2 is 1.714 Å according to the previous work.…”

“…The in situ formation of VH 2 , MgS, and Mg 2 Ni/Mg 2 NiH 4 increase the free energy and reactivity . Additionally, a significant number of phase interfaces exist within the Mg or MgH 2 matrix (Figures S9 and S10), encompassing interfaces between catalytic phases and the catalytic host, as well as interfaces among catalytic phases, which provide ample channels for the diffusion of hydrogen. , …”

“…From this point, transition metal catalysts (Fe, Co, Ni, V, etc.) with unique 3d electronic structures and excellent affinity toward H are efficient to facilitate the hydrogen storage performance of MgH 2 . − Since the interaction between unsaturated d-electrons and the H 1s orbital electrons can weaken the bond strength of Mg–H bond. ,, V-based transition metal compounds with strong affinity to H are widely employed as catalysts, and many advanced fabrication methods have been proposed to tailor the morphology and composition, endowing superior catalytic activity. ,,− It is found that the high-valent V 6 O 13 is transformed into low-valent (V metal) during reaction with MgH 2 , and the strong bonding interactions between V and H cause weaker structural stability and higher surface states of MgH 2 . Meanwhile, compared with single-component catalysts, multicomponent catalysts with excellent activity will provide extra synergistic effect in the presence of stable or unstable catalytic species. ,, So far, considerable research has been dedicated to the design of catalyst components and compositions.…”