Karimi Fahim, Pranzas P Klaus, Pistidda Claudio, Puszkiel Julián A, Milanese Chiara, Vainio Ulla, Paskevicius Mark, Emmler Thomas, Santoru Antonio, Utke Rapee, Tolkiehn Martin, Minella Christian B, Chaudhary Anna-Lisa, Boerries Stefan, Buckley Craig E, Enzo Stefano, Schreyer Andreas, Klassen Thomas, Dornheim Martin
Helmholtz-Zentrum Geesthacht, Max-Planck Str. 1, 21502 Geesthacht, Germany.
Phys Chem Chem Phys. 2015 Nov 7;17(41):27328-42. doi: 10.1039/c5cp03557k.
Designing safe, compact and high capacity hydrogen storage systems is the key step towards introducing a pollutant free hydrogen technology into a broad field of applications. Due to the chemical bonds of hydrogen-metal atoms, metal hydrides provide high energy density in safe hydrogen storage media. Reactive hydride composites (RHCs) are a promising class of high capacity solid state hydrogen storage systems. Ca(BH4)2 + MgH2 with a hydrogen content of 8.4 wt% is one of the most promising members of the RHCs. However, its relatively high desorption temperature of ∼350 °C is a major drawback to meeting the requirements for practical application. In this work, by using NbF5 as an additive, the dehydrogenation temperature of this RHC was significantly decreased. To elucidate the role of NbF5 in enhancing the desorption properties of the Ca(BH4)2 + MgH2 (Ca-RHC), a comprehensive investigation was carried out via manometric measurements, mass spectrometry, Differential Scanning Calorimetry (DSC), in situ Synchrotron Radiation-Powder X-ray Diffraction (SR-PXD), X-ray Absorption Spectroscopy (XAS), Anomalous Small-Angle X-ray Scattering (ASAXS), Scanning and Transmission Electron Microscopy (SEM, TEM) and Nuclear Magnetic Resonance (NMR) techniques.
设计安全、紧凑且高容量的储氢系统是将无污染氢技术引入广泛应用领域的关键一步。由于氢与金属原子之间的化学键，金属氢化物在安全的储氢介质中提供了高能量密度。反应性氢化物复合材料（RHCs）是一类很有前景的高容量固态储氢系统。氢含量为8.4 wt%的Ca(BH4)2 + MgH2是RHCs中最有前景的成员之一。然而，其约350 °C的相对较高的脱附温度是满足实际应用要求的一个主要缺点。在这项工作中，通过使用NbF5作为添加剂，该RHC的脱氢温度显著降低。为了阐明NbF5在增强Ca(BH4)2 + MgH2（Ca-RHC）脱附性能中的作用，通过压力测量、质谱分析、差示扫描量热法（DSC）、原位同步辐射粉末X射线衍射（SR-PXD）、X射线吸收光谱（XAS）、反常小角X射线散射（ASAXS）、扫描和透射电子显微镜（SEM、TEM）以及核磁共振（NMR）技术进行了全面研究。
