摘要
In this work, porous boron nitride (pBN) and NbF5 were used to improve the hydrogen storage performance of magnesium hydride (MgH2), especially the reversibility and dehydrogenation kinetics. We also carried out a series of control experiments to optimize the sample preparation method and addition amount of pBN. Comparing with the pristine MgH2 system, the as-prepared MgH2/NbF5@pBN sample exhibits promoting dehydrogenation kinetics. And it rapidly began to release hydrogen from around 230 degrees C, which was 140 degrees C lower. Moreover, it took 10 min during all the dehydrogenation process. A series of phase and chemical state analyses was used to study the enhanced effects of NbF5@pBN on the reversible hydrogen storage performance of MgH2. And the study demonstrates pBN is an effective additive as confinement medium and catalysis of the surface dangling-bond for improving the reversible dehydrogenation of MgH2. NbF5 could also act as catalysts. Therefore, the prominently improved dehydrogenation performance of MgH2 should be ascribed to a synergistic effect of nanoconfinement and catalysis.
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单位青岛大学