Effect of Mg–Nb oxides addition on hydrogen sorption in MgH2

Formation of Mg–Nb–O rock salt structures in a series of mechanochemically activated MgH2 + nNb2O5 (n = 0.083–1.50) mixtures

“…Formation of Mg 4 Nb 2 O 9 only on this composition is surprising, but it may be characteristic of this specific stoichiometry. In the literature, the studies of Rahman et al employing Mg 4 Nb 2 O 9 suggest that, sorption of hydrogen by Mg 4 Nb 2 O 9 surface is feeble and also the Mg 4 Nb 2 O 9 admixed MgH 2 system does not exhibit any pronounced hydrogen storage performance [54,55]. With these inputs we believe that Mg 4 Nb 2 O 9 phase may not have any significant role in the catalysis of MgH 2 eNb 2 O 5 hydrogen storage system.…”

Effects of BaRuO3 addition on hydrogen desorption in MgH2

“…Due to the progressive approaching of the equilibrium temperature at the desorption pressure (0.1 MPa) on decreasing temperatures [26], a correction of the kinetic constants obtained at various temperatures with a constant pressure has been suggested [44].…”

“…The addition of niobia (Nb 2 O 5 ), in particular, has demonstrated an increase of reactivity in MgH 2 with respect to H 2 uptake/release [9,[21][22][23][24][25]. Recently, the interaction of hydrogen with MgH 2 in presence of ternary Mg-Nb oxides has been studied [26], suggesting a prominent effect for the system Mg 3 Nb 6 O 11 . However, the exact role of additives on reaction mechanism still remained unclear.…”

“…In addition, the interaction of H 2 with TMOs has drawn attention in order to understand their specific role on H 2 ab/desorption reactions in MgH 2 [27][28][29][30][31][32]. In particular, it has been suggested that the occurrence of a hydrogen absorption in the additive oxide phase may facilitate the overcome of the MgO layer formed at the surface of the MgH 2 particles, leading to an improved reaction kinetics [25,26].…”

Synthesis of catalytically active rock salt structured Mg x Nb 1−x O nanoparticles for MgH 2 system

“…In the present study our focus was mainly to analyze the formation of the MgeNbeO type product when Mg and Nb are reacted in a 1:2 atomic ratio. This ratio was chosen because the literature suggests the existence of many MgeNbeO phases, which range from the Nb dissolved solid solution of MgO to the Nb rich stable compound MgNb 2 O 6 [15e17], which enhance the desorption of MgH 2 [18]. Additionally, in order to check the possible formation of MgNb 2 O x phases as discussed in Ref [7], a 1:2 atomic ratio of Mg/Nb is required.…”