Order-disorder and ionic conductivity in calcium nitride-hydride

Gavin John Irvine; Ronald I Smith; Martin Owen Jones; John Thomas Sirr Irvine

doi:10.1038/s41467-023-40025-2

Order-disorder and ionic conductivity in calcium nitride-hydride

Gavin John Irvine^*, Ronald I Smith, Martin Owen Jones, John Thomas Sirr Irvine^*

^*Corresponding author for this work

Research output: Contribution to journal › Article › peer-review

2 Citations (Scopus)

10 Downloads (Pure)

Abstract

Recently nitrogen-hydrogen compounds have successfully been applied as co-catalysts for mild conditions ammonia synthesis. Ca₂NH was shown to act as a H₂ sink during reaction, with H atoms from its lattice being incorporated into the NH₃(g) product. Thus the ionic transport and diffusion properties of the N–H co-catalyst are fundamentally important to understanding and developing such syntheses. Here we show hydride ion conduction in these materials. Two distinct calcium nitride-hydride Ca₂NH phases, prepared via different synthetic paths are found to show dramatically different properties. One phase (β) shows fast hydride ionic conduction properties (0.08 S/cm at 600 °C), on a par with the best binary ionic hydrides and 10 times higher than CaH₂, whilst the other (α) is 100 times less conductive. An in situ combined analysis techniques reveals that the effective β-phase conducts ions via a vacancy-mediated phenomenon in which the charge carrier concentration is dependent on the ion concentration in the secondary site and by extension the vacancy concentration in the main site.

Original language	English
Article number	4389
Number of pages	8
Journal	Nature Communications
Volume	14
DOIs	https://doi.org/10.1038/s41467-023-40025-2
Publication status	Published - 20 Jul 2023

Keywords

Hydride ion conductor
Ammonia synthesis
Combined analysis
Nitride-hydride

Access to Document

10.1038/s41467-023-40025-2Licence: CC BY

Irvine_2023_NC_Order-disoder_CC
Copyright © The Author(s) 2023. Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.
Final published version, 1.26 MBLicence: CC BY

ISIS Studentship - John Irvine: Development of Combined In situ Neutron Diffraction and Electrochemical Studies
Irvine, J. T. S. (PI)
Science & Technology Facilities Council
1/10/16 → 30/09/20
Project: Studentship

Order-Disorder and Ionic Conductivity in Calcium Nitride-Hydride (dataset)
Irvine, G. J. (Creator) & Irvine, J. T. S. (Contributor), University of St Andrews, 31 Jul 2023
DOI: 10.17630/6760d05d-114b-47ee-99bf-c9481cf25a55
Dataset

File

Cite this

@article{52a18645b3a946f08b1005ee15939712,

title = "Order-disorder and ionic conductivity in calcium nitride-hydride",

abstract = "Recently nitrogen-hydrogen compounds have successfully been applied as co-catalysts for mild conditions ammonia synthesis. Ca2NH was shown to act as a H2 sink during reaction, with H atoms from its lattice being incorporated into the NH3(g) product. Thus the ionic transport and diffusion properties of the N–H co-catalyst are fundamentally important to understanding and developing such syntheses. Here we show hydride ion conduction in these materials. Two distinct calcium nitride-hydride Ca2NH phases, prepared via different synthetic paths are found to show dramatically different properties. One phase (β) shows fast hydride ionic conduction properties (0.08 S/cm at 600 °C), on a par with the best binary ionic hydrides and 10 times higher than CaH2, whilst the other (α) is 100 times less conductive. An in situ combined analysis techniques reveals that the effective β-phase conducts ions via a vacancy-mediated phenomenon in which the charge carrier concentration is dependent on the ion concentration in the secondary site and by extension the vacancy concentration in the main site.",

keywords = "Hydride ion conductor, Ammonia synthesis, Combined analysis, Nitride-hydride",

author = "Irvine, {Gavin John} and Smith, {Ronald I} and Jones, {Martin Owen} and Irvine, {John Thomas Sirr}",

note = "Funding: Prof John TS Irvine and Prof Martin Owen Jones: STFC 5005—Development of Combined In situ Neutron Diffraction and Electrochemical Studies. ",

year = "2023",

month = jul,

day = "20",

doi = "10.1038/s41467-023-40025-2",

language = "English",

volume = "14",

journal = "Nature Communications",

issn = "2041-1723",

publisher = "Nature publishing group",

}

TY - JOUR

T1 - Order-disorder and ionic conductivity in calcium nitride-hydride

AU - Irvine, Gavin John

AU - Smith, Ronald I

AU - Jones, Martin Owen

AU - Irvine, John Thomas Sirr

N1 - Funding: Prof John TS Irvine and Prof Martin Owen Jones: STFC 5005—Development of Combined In situ Neutron Diffraction and Electrochemical Studies.

PY - 2023/7/20

Y1 - 2023/7/20

N2 - Recently nitrogen-hydrogen compounds have successfully been applied as co-catalysts for mild conditions ammonia synthesis. Ca2NH was shown to act as a H2 sink during reaction, with H atoms from its lattice being incorporated into the NH3(g) product. Thus the ionic transport and diffusion properties of the N–H co-catalyst are fundamentally important to understanding and developing such syntheses. Here we show hydride ion conduction in these materials. Two distinct calcium nitride-hydride Ca2NH phases, prepared via different synthetic paths are found to show dramatically different properties. One phase (β) shows fast hydride ionic conduction properties (0.08 S/cm at 600 °C), on a par with the best binary ionic hydrides and 10 times higher than CaH2, whilst the other (α) is 100 times less conductive. An in situ combined analysis techniques reveals that the effective β-phase conducts ions via a vacancy-mediated phenomenon in which the charge carrier concentration is dependent on the ion concentration in the secondary site and by extension the vacancy concentration in the main site.

AB - Recently nitrogen-hydrogen compounds have successfully been applied as co-catalysts for mild conditions ammonia synthesis. Ca2NH was shown to act as a H2 sink during reaction, with H atoms from its lattice being incorporated into the NH3(g) product. Thus the ionic transport and diffusion properties of the N–H co-catalyst are fundamentally important to understanding and developing such syntheses. Here we show hydride ion conduction in these materials. Two distinct calcium nitride-hydride Ca2NH phases, prepared via different synthetic paths are found to show dramatically different properties. One phase (β) shows fast hydride ionic conduction properties (0.08 S/cm at 600 °C), on a par with the best binary ionic hydrides and 10 times higher than CaH2, whilst the other (α) is 100 times less conductive. An in situ combined analysis techniques reveals that the effective β-phase conducts ions via a vacancy-mediated phenomenon in which the charge carrier concentration is dependent on the ion concentration in the secondary site and by extension the vacancy concentration in the main site.

KW - Hydride ion conductor

KW - Ammonia synthesis

KW - Combined analysis

KW - Nitride-hydride

U2 - 10.1038/s41467-023-40025-2

DO - 10.1038/s41467-023-40025-2

M3 - Article

SN - 2041-1723

VL - 14

JO - Nature Communications

JF - Nature Communications

M1 - 4389

ER -

Order-disorder and ionic conductivity in calcium nitride-hydride

Abstract

Keywords

Access to Document

Fingerprint

Projects

ISIS Studentship - John Irvine: Development of Combined In situ Neutron Diffraction and Electrochemical Studies

Datasets

Order-Disorder and Ionic Conductivity in Calcium Nitride-Hydride (dataset)

Cite this