Insights into the Rb-Mg-N-H System: an Ordered Mixed Amide/Imide Phase and a Disordered Amide/Hydride Solid Solution

Antonio Santoru; Claudio Pistidda; Matteo Brighi; Michele R Chierotti; Michael Heere; Fahim Karimi; Hujun Cao; Giovanni Capurso; Anna-Lisa Chaudhary; Gökhan Gizer; Sebastiano Garroni; Magnus H Sørby; Bjørn C Hauback; Radovan Černý; Thomas Klassen; Martin Dornheim

doi:10.1021/acs.inorgchem.7b03232

Insights into the Rb-Mg-N-H System: an Ordered Mixed Amide/Imide Phase and a Disordered Amide/Hydride Solid Solution

Inorg Chem. 2018 Mar 19;57(6):3197-3205. doi: 10.1021/acs.inorgchem.7b03232. Epub 2018 Mar 7.

Authors

Antonio Santoru¹, Claudio Pistidda¹, Matteo Brighi², Michele R Chierotti³, Michael Heere⁴, Fahim Karimi¹, Hujun Cao¹, Giovanni Capurso¹, Anna-Lisa Chaudhary¹, Gökhan Gizer¹, Sebastiano Garroni^{5

6}, Magnus H Sørby⁴, Bjørn C Hauback⁴, Radovan Černý², Thomas Klassen¹, Martin Dornheim¹

Affiliations

¹ Nanotechnology Department , Helmholtz-Zentrum Geesthacht Max-Planck Straße 1 , 21502 Geesthacht , Germany.
² Laboratory of Crystallography, Department of Quantum Matter Physics , University of Geneva , Quai Ernest-Ansermet 24 , Ch-1211 Geneva , Switzerland.
³ Department of Chemistry and NIS centre , University of Torino , Via Giuria 7 , 10125 Torino , Italy.
⁴ Physics Department , Institute for Energy Technology (IFE) , NO-2027 Kjeller , Norway.
⁵ International Research Centre in Critical Raw Materials-ICCRAM , Universidad de Burgos , Plaza Misael Banuelos s/n , 09001 Burgos , Spain.
⁶ Advanced Materials, Nuclear Technology and Applied Bio/Nanotechnology, Consolidated Research Unit UIC-154 , Universidad de Burgos , Hospital del Rey s/n , 09001 Burgos , Spain.

PMID: 29512391
DOI: 10.1021/acs.inorgchem.7b03232

Abstract

The crystal structure of a mixed amide-imide phase, RbMgND₂ND, has been solved in the orthorhombic space group Pnma ( a = 9.55256(31), b = 3.70772(11) and c = 10.08308(32) Å). A new metal amide-hydride solid solution, Rb(NH₂) _xH_{(1- x)}, has been isolated and characterized in the entire compositional range. The profound analogies, as well as the subtle differences, with the crystal chemistry of KMgND₂ND and K(NH₂) _xH_{1- x} are thoroughly discussed. This approach suggests that the comparable performances obtained using K- and Rb-based additives for the Mg(NH₂)₂- 2LiH and 2LiN H₂-MgH₂ hydrogen storage systems are likely to depend on the structural similarities of possible reaction products and intermediates.