Hydrogenation properties of LixSr1−xAlSi studied by quantum-chemical methods (0≤x≤1) and in-situ neutron powder diffraction (x=1)

•In-situ neutron powder diffraction of LiAlSi under high D2 pressure was carried out.•LiAlSi decomposes according to LiAlSi + ½ H2 = LiH + Al + Si.•Mixed crystals LixSr1-xAlSi and LixSr1-xAlSiH were studied theoretically.

In-situ neutron powder diffraction studies of the Half-Heusler phase LiAlSi under high deuterium pressures and first principle calculations of solid solutions of LixSr1−xAlSi and their hydrides LixSr1−xAlSiH were carried out. In contrast to an earlier study, there is no experimental evidence for hydrogen (deuterium) uptake up to gas pressures of 15 MPa and temperatures of 550 °C. Instead a slow decomposition reaction according to LiAlSi+1/2H2=LiH+Al+Si was found by in-situ neutron powder diffraction. Theoretical calculations by DFT methods on hypothetical solid solutions of LixSr1−xAlSi show the LiAlSi type to be the energetically most stable structure for 0.7

Graphical abstractIn-situ neutron powder diffraction of LiAlSi under high D2 pressure.Figure optionsDownload full-size imageDownload as PowerPoint slide