Hydrogenation Study of NaF/NaH/MgB2 Reactive Hydride Composites

作者：Carrillo Bucio J L; Saldan I; Pistidda C; Karimi F; Suarez Alcantara K^*; Dornheim M; Klassen T

来源：Journal of Physical Chemistry C, 2017, 121(8): 4093-4102.

DOI：10.1021/acs.jpcc.6b09776

The hydrogenation of NaF/9NaH + 5MgB(2) and NaF/2NaH + 1.5MgB(2) reactive hydride composites (RHC) was studied by volumetric titration (kinetics and PCI curves), in situ synchrotron radiation powder X-ray diffraction (SR-PXD), high-pressure differential scanning calorimetry (HP-DSC), Fourier transform infrared spectroscopy (FT-IR), and scanning electron microscope (SEM). A hydrogen uptake between 4.1 and 4.8 wt % was observed when the H-2 pressure was in the range between 25 and SO bar, and the temperature was kept constant at 325 degrees C. PCI curves indicate a hydrogenation equilibrium pressure of 2 and 8 bar at 325 degrees C for NaF/9NaH + 5MgB(2) and NaF/2NaH + 1.5MgB(2), respectively. Synchrotron radiation powder X-ray diffraction revealed the formation of solid solutions of NaF-NaH after milling and a change in the reaction pathway compared to a reported nondoped 2NaH + MgB2 reactive hydride composite. Formation of the stable side-product NaMgH2F was found as a drawback for hydrogen storage capacity and reversibility. FT-1R indicates no hydrogen to fluorine substitution in the NaBH4 product.

• 出版日期2017-3-2