A comparison of the reactivity of the lattice nitrogen in tungsten substituted Co3Mo3N and Ni2Mo3N

Al Sobhi, S., Alshibane, I., Catlow, C. R. A., Daisley, A., Hargreaves, J. S.J. , Hector, A. L., Higham, M. D. and Zeinalipour-Yazdi, C. D. (2023) A comparison of the reactivity of the lattice nitrogen in tungsten substituted Co3Mo3N and Ni2Mo3N. Chemsuschem, 16(22), e202300945. (doi: 10.1002/cssc.202300945) (PMID:37703103)

Abstract

The effect of the partial substitution of Mo with W in Co3Mo3N and Ni2Mo3N on ammonia synthesis activity and lattice nitrogen reactivity has been investigated. This is of interest as the coordination environment of lattice N is changed by this process. When tungsten was introduced into the metal nitrides by substitution of Mo atoms, the catalytic performance was observed to have decreased. As expected, Co3Mo3N was reduced to Co6Mo6N under a 3 : 1 ratio of H2/Ar. Co3Mo2.6W0.4N was also shown to lose a large percentage of lattice nitrogen under these conditions. The bulk lattice nitrogen in Ni2Mo3N and Ni2Mo2.8W0.2N was unreactive, demonstrating that substitution with tungsten does not have a significant effect on lattice N reactivity. Computational calculations reveal that the vacancy formation energy for Ni2Mo3N is more endothermic than Co3Mo3N. Furthermore, calculations suggest that the inclusion of W does not have a substantial impact on the surface N vacancy formation energy or the N2 adsorption and activation at the vacancy site.

• Item Type: Articles
• Additional Information: The authors would like to acknowledge the EPSRC for the research grants EP/T027851/1, EP/T028416/1 and EP/T028629/1 for the financial support of this project, and the UK Catalysis Hub Consortium(funded by EPSRC(Grants EP/R026815/1)) for the provision of additional resources. The authors acknowledge the STFC(SCARF)and UK National Supercomputing Service (ARCHER2) for the provision of computational resources, the latter enabled via membership of the MCC (EP/L000202).
• Keywords: Metal nitride, Mars-van Krevelen, DFT, nitrogen vacancy, ammonia synthesis.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Daisley, Miss Angela and Alshibane, Dr Ihfaf and Hargreaves, Professor Justin
• Authors: Al Sobhi, S., Alshibane, I., Catlow, C. R. A., Daisley, A., Hargreaves, J. S.J., Hector, A. L., Higham, M. D., and Zeinalipour-Yazdi, C. D.
• College/School: College of Science and Engineering > School of Chemistry
• Journal Name: Chemsuschem
• Publisher: Wiley
• ISSN: 1864-5631
• ISSN (Online): 1864-564X
• Published Online: 13 September 2023
• Copyright Holders: Copyright © 2023 The Authors
• First Published: First published in Chemsuschem 16(22): e202300945
• Publisher Policy: Reproduced under a Creative Commons License

Project Code	Award No	Project Name	Principal Investigator	Funder's Name	Funder Ref	Lead Dept
308459		Next generation ammonia synthesis: a highly integrated computational modelling and experimental approach	Justin Hargreaves	Engineering and Physical Sciences Research Council (EPSRC)	EP/T027851/1	Chemistry