Ab initio study on destabilizing mechanism of magnesium hydride by Ti and Fe co-doping

Exploring the Hydrogen Storage Performance of MgH2 Catalyzed by Two Transition Metals Ni and Co by In‐situ Calorimetry and Density Functional Theory Calculations

“…In the case of MgH 2 (Figure 8(a)), the DOS of Mg‐3 s was overlapped with those of H‐1 s in the energy range of −6.7~0.3 eV and 3~5 eV, suggesting a strong hybridization between H‐1 s and Mg‐3 s. Their orbital hybridization weakened in the presence of Ni and Co atoms (Figure 8(b)), meaning the weakened bond strength between Mg and H. Meanwhile, new orbital hybridized peaks were formed in the energy range of −2.5~−0.5 eV, which also intensely overlapped with Co‐3d and Ni‐3d, showing electron transfer between Ni/Co and MgH 2 . In summary, the Mg atoms near the Ni and Co sacrificed the orbital hybridization with the H atoms and increased the hybridization with the Ni/Co, which results in the weakening of the orbital hybridization between the Mg atoms and the H atoms [6b,7e,h] . Moreover, the narrowed bandgap of MgH 2 after modifying with Ni and Co demonstrated the enhanced electron transfer ability.…”

“…Adding additives to MgH 2 is one of the effective methods to overcome thermodynamic and kinetic drawbacks of MgH 2 in hydrogen storage reactions. Previous studies have confirmed that the transition metals (TM) play a prominent catalytic effect on enhancing the hydrogen storage properties of MgH 2 [3c,6b,7] . Loulidi et al [7g] .…”

“…showed that co‐doping with Ni and Y can effectively improve the dehydrogenation properties of destabilized MgH 2 . Moreover, Um et al [6b,14] . also demonstrated that co‐doping with Ti and Fe can reduce the stability of MgH 2 more effectively than that of Fe or Ti by Ab initio study.…”

Catalytic characteristics of titanium‐( IV )‐isopropoxide ( TTIP ) on de/re‐hydrogenation of wet ball‐milled MgH 2 / Mg

“…29-37 29-37 Several research groups have also looked into various transition metal-based catalysts in order to increase the performance of Mg/MgH 2 . 18,23,24,[38][39][40][41][42][43][44][45] The use of TiVO 3.5 catalyst resulted in a significant improvement in MgH 2 storage kinetics. 46 TiF 4 is a good catalyst for enhancing the MgH 2 re/dehydrogenation kinetics.…”

“…Researchers have published their findings on Mg‐based alloys for hydrogen storage applications 29‐37 . Several research groups have also looked into various transition metal‐based catalysts in order to increase the performance of Mg/MgH 2 18,23,24,38‐45 . The use of TiVO 3.5 catalyst resulted in a significant improvement in MgH 2 storage kinetics 46 .…”