Barale Jussara, Deledda Stefano, Dematteis Erika M, Sørby Magnus H, Baricco Marcello, Hauback Bjørn C
Department of Chemistry, Inter-departmental Center Nanostructured Interfaces and Surfaces (NIS) and INSTM, University of Turin, Via Pietro Giuria 7, 10125, Torino, Italy.
Department for Neutron Materials Characterization, Institute for Energy Technology (IFE), PO Box 40 18, NO-2027, Kjeller, Norway.
Sci Rep. 2020 Jun 2;10(1):9000. doi: 10.1038/s41598-020-65774-8.
The formation, structure and deuterium desorption properties of MgFeCoD (0 ≤ x ≤ 1 and 5 ≤ y ≤ 6) complex hydrides were investigated. The synthesis was carried out by reactive ball milling, using a mixture of powders of the parent elements in D atmosphere. The formation of quaternary deuterides was identified from Rietveld refinements of powder X-Ray diffraction and powder neutron diffraction patterns, and from infrared attenuated total reflectance analysis. It was observed that the crystal structure of deuterides depends on the transition metal fraction. For Co-rich compositions, i.e. up to x = 0.1, hydrides have the tetragonal distorted CaF-type structure (space group P4/nmm) of MgCoD at room temperature. For Fe-rich compositions, i.e. x ≥ 0.5, a cubic hydride is observed, with the same KPtCl-type structure (space group Fm[Formula: see text]m) as MgFeD and as MgCoD at high temperatures. For x = 0.3, both the cubic and the tetragonal deuterides are detected. Differential scanning calorimetry coupled with thermogravimetric and temperature programmed desorption analyses show rather similar deuterium desorption properties for all samples, without significant changes as a function of composition. Finally, hydrogen sorption experiments performed for MgFeCoH at 30 bar of H and 673 K showed reversible reactions, with good kinetic for both absorption and desorption of hydrogen.
研究了MgFeCoD（0≤x≤1且5≤y≤6）复合氢化物的形成、结构和氘解吸性能。合成通过反应球磨进行，在D气氛中使用母体元素的粉末混合物。通过粉末X射线衍射和粉末中子衍射图谱的Rietveld精修以及红外衰减全反射分析确定了四元氘化物的形成。观察到氘化物的晶体结构取决于过渡金属分数。对于富Co组成，即x≤0.1，氢化物在室温下具有MgCoD的四方畸变CaF型结构（空间群P4/nmm）。对于富Fe组成，即x≥0.5，观察到一种立方氢化物，在高温下具有与MgFeD和MgCoD相同的KPtCl型结构（空间群Fm[公式：见正文]m）。对于x = 0.3，检测到立方和四方氘化物。差示扫描量热法与热重分析和程序升温脱附分析相结合表明，所有样品的氘解吸性能相当相似，不会随组成发生显著变化。最后，在30 bar的H和673 K下对MgFeCoH进行的氢吸附实验表明反应是可逆的，氢的吸收和解吸动力学良好。
