In this work, one-dimensional NiMoO₄ and CoMoO₄ nanorods are prepared and introduced into MgH₂ to improve its hydrogen storage properties. It is observed that the MgH₂–NiMoO₄ system exhibits lower dehydrogenation temperature and faster kinetics than the MgH₂–CoMoO₄ system and pure MgH₂, indicating the superior promoting effect of NiMoO₄ over CoMoO₄. Concretely, NiMoO₄ reacts with MgH₂ during the first dehydrogenation to in situ form Mg₂Ni and Mo⁰, both of which are crucial factors for the following hydrogen cycling process. The ‘Mg₂Ni/Mg₂NiH₄’ mutual transformation upon hydrogen release/uptake is the well-known ‘hydrogen pump’ effect which boosts the hydrogen storage performance of MgH₂. Moreover, theoretical calculations reveal the dual roles of Mo⁰ played for the hydrogen storage in MgH₂: i) it accelerates the hydrogen de/absorption of MgH₂ through weakening the Mg–H bonding; ii) it facilitates the mutual ‘Mg₂Ni/Mg₂NiH₄’ transformation as the formation energy of Mg₂NiH₄ decreases under the influence of Mo⁰, which we call ‘facilitated hydrogen pump’ effect in this work. Ascribing to the collaborative action between Ni- and Mo- containing species, the hydrogen storage kinetics of MgH₂ has been accelerated.

在这项工作中，制备一维NiMoO ₄和CoMoO ₄纳米棒并将其引入MgH _2中以改善其储氢性能。可以看出，MgH ₂ -NiMoO ₄体系比MgH ₂ -CoMoO ₄体系和纯MgH ₂表现出较低的脱氢温度和更快的动力学，表明NiMoO _4的促进作用优于CoMoO ₄。具体地，在第一次脱氢过程中，NiMoO ₄与MgH ₂反应以原位形成Mg ₂ Ni和Mo ⁰，这都是随后的氢循环过程的关键因素。氢释放/吸收时的“ Mg ₂ Ni / Mg ₂ NiH ₄ ”互变是众所周知的“氢泵”效应，其提高了MgH ₂的储氢性能。此外，理论计算揭示Mo的双重角色⁰中的MgH效力于储氢₂：i）其加速了氢解的MgH的/吸收₂通过弱化的MgH粘接; ⅱ）它有利于相互'MG ₂的Ni / Mg的₂ NIH ₄ '转化为镁的形成能量₂ NIH ₄在Mo ⁰的影响下降低，在这项工作中我们称之为“促进氢泵”效应。由于含镍和含钼物种之间的协同作用，MgH ₂的氢存储动力学得到了加速。