Crystal structure and hydrogenation ...
Type de document :
Article dans une revue scientifique
URL permanente :
Titre :
Crystal structure and hydrogenation properties of Pd5As
Auteur(s) :
Kohlmann, Holger [Auteur]
Vasseur, M. [Auteur]
Sayede, Adlane [Auteur]
Unité de Catalyse et Chimie du Solide - UMR 8181 [UCCS]
Lefevre, Gauthier [Auteur]
Unité de Catalyse et Chimie du Solide - UMR 8181 [UCCS]
Sander, J.M. [Auteur]
Doyle, S. [Auteur]
Vasseur, M. [Auteur]
Sayede, Adlane [Auteur]
Unité de Catalyse et Chimie du Solide - UMR 8181 [UCCS]
Lefevre, Gauthier [Auteur]
Unité de Catalyse et Chimie du Solide - UMR 8181 [UCCS]
Sander, J.M. [Auteur]
Doyle, S. [Auteur]
Titre de la revue :
Journal of Alloys and Compounds
Numéro :
664
Pagination :
256-265
Date de publication :
2016-04-15
Discipline(s) HAL :
Chimie/Chimie inorganique
Résumé en anglais : [en]
The crystal structure of Pd5As was refined simultaneously from laboratory X-ray, synchrotron and neutron powder diffraction data (space group C2/m, a = 551.82(2) pm, b = 774.50(3) pm, c = 842.13(4), β = 99.037(2)°, Z = 4). ...
Lire la suite >The crystal structure of Pd5As was refined simultaneously from laboratory X-ray, synchrotron and neutron powder diffraction data (space group C2/m, a = 551.82(2) pm, b = 774.50(3) pm, c = 842.13(4), β = 99.037(2)°, Z = 4). This is in contrast to earlier work, which describes the structure in the non-centrosymmetric space group C2. Eight palladium atoms form a bicapped trigonal prism around arsenic. Two such polyhedra are connected by a common edge to double prisms (average distance As–Pd 252 pm). Palladium has got coordination numbers of 11 (average distance 276 pm) or 12 (average distance of 278 pm). The crystal structure of Pd5As represents a strongly distorted cubic closest packing as proven by crystallographic group–subgroup relationships. Pd5As does not take up hydrogen up to 5.0 MPa hydrogen pressure and temperatures up to 723 K. Quantum-mechanical calculations using DFT methods using an ab initio evolutionary algorithm confirm the crystal structure of Pd5As and reveal the stability of a hypothetical hydride Pd5AsH. The lack of reactivity might be due to kinetic hindrance because of an endothermic rearrangement of the metal matrix necessary for hydrogen incorporation. Above 5.8 GPa, however, this phase transition becomes thermodynamically favourable, making hydrogenation of Pd5As likely to occur.Lire moins >
Lire la suite >The crystal structure of Pd5As was refined simultaneously from laboratory X-ray, synchrotron and neutron powder diffraction data (space group C2/m, a = 551.82(2) pm, b = 774.50(3) pm, c = 842.13(4), β = 99.037(2)°, Z = 4). This is in contrast to earlier work, which describes the structure in the non-centrosymmetric space group C2. Eight palladium atoms form a bicapped trigonal prism around arsenic. Two such polyhedra are connected by a common edge to double prisms (average distance As–Pd 252 pm). Palladium has got coordination numbers of 11 (average distance 276 pm) or 12 (average distance of 278 pm). The crystal structure of Pd5As represents a strongly distorted cubic closest packing as proven by crystallographic group–subgroup relationships. Pd5As does not take up hydrogen up to 5.0 MPa hydrogen pressure and temperatures up to 723 K. Quantum-mechanical calculations using DFT methods using an ab initio evolutionary algorithm confirm the crystal structure of Pd5As and reveal the stability of a hypothetical hydride Pd5AsH. The lack of reactivity might be due to kinetic hindrance because of an endothermic rearrangement of the metal matrix necessary for hydrogen incorporation. Above 5.8 GPa, however, this phase transition becomes thermodynamically favourable, making hydrogenation of Pd5As likely to occur.Lire moins >
Langue :
Anglais
Audience :
Internationale
Vulgarisation :
Non
Établissement(s) :
ENSCL
CNRS
Centrale Lille
Univ. Artois
Université de Lille
CNRS
Centrale Lille
Univ. Artois
Université de Lille
Collections :
Équipe(s) de recherche :
Couches minces & nanomatériaux (CMNM)
Date de dépôt :
2019-09-25T14:05:21Z
2021-05-18T12:55:37Z
2021-05-18T12:55:37Z