Skip navigation

DFT-D3 study of H 2 and N 2 chemisorption over cobalt promoted Ta 3 N 5-(100), (010) and (001) surfaces

DFT-D3 study of H 2 and N 2 chemisorption over cobalt promoted Ta 3 N 5-(100), (010) and (001) surfaces

Zeinalipour-Yazdi, Constantinos D. ORCID: 0000-0002-8388-1549, Hargreaves, Justin S. J., Laassiri, Said and Catlow, C. Richard A. (2017) DFT-D3 study of H 2 and N 2 chemisorption over cobalt promoted Ta 3 N 5-(100), (010) and (001) surfaces. Physical Chemistry Chemical Physics, 2017 (19). pp. 11968-11974. ISSN 1463-9076 (Print), 1463-9084 (Online) (doi:https://doi.org/10.1039/C7CP00806F)

[img]
Preview
PDF (Publisher's PDF - Open Access)
21485 ZEINALIPOUR-YAZDI_DFT-D3_Study_of H 2_and_N 2_Chemisorption_(OA)_2017.pdf - Published Version
Available under License Creative Commons Attribution.

Download (2MB) | Preview

Abstract

The reactants for ammonia synthesis have been studied, employing density functional theory (DFT), with respect to their adsorption on tantalum nitride surfaces. The adsorption of nitrogen was found to be mostly molecular and non-activated with side-on, end-on and tilt configurations. At bridging nitrogen sites (Ta–N–Ta) it results in an azide functional group formation with a formation energy of 205 kJ mol−1. H2 was found also to chemisorb molecularly with an adsorption energy in the range −81 to −91 kJ mol−1. At bridging nitrogen sites it adsorbs dissociatively forming >NH groups with an exothermic formation energy of −175 kJ mol−1 per H2. The nitrogen vacancy formation energies were relatively high compared to other metal nitrides found to be 2.89 eV, 2.32 eV and 1.95 eV for plain, surface co-adsorbed cobalt and sub-surface co-adsorbed cobalt Ta3N5-(010). Co-adsorption of cobalt was found to occur mostly at nitrogen rich sites of the surface with an adsorption energy that ranged between −200 to −400 kJ mol−1. The co-adsorption of cobalt was found to enhance the dissociation of molecular hydrogen on the surface of Ta3N5. The studies offer significant new insight with respect to the chemistry of N2 and H2 with tantalum nitride surfaces in the presence of cobalt promoters.

Item Type: Article
Additional Information: Open Access. This article is licensed under a Creative Commons Attribution 3.0 Unported Licence.
Uncontrolled Keywords: Ta3N5, tantalum nitride, DFT, H2 adsorption, N2 adsorption, nitrogen activation, ammonia synthesis
Subjects: Q Science > QD Chemistry
Faculty / Department / Research Group: Faculty of Engineering & Science
Faculty of Engineering & Science > Department of Pharmaceutical, Chemical & Environmental Sciences
Last Modified: 06 Oct 2018 02:01
Selected for GREAT 2016: None
Selected for GREAT 2017: None
Selected for GREAT 2018: None
Selected for GREAT 2019: None
URI: http://gala.gre.ac.uk/id/eprint/21485

Actions (login required)

View Item View Item

Downloads

Downloads per month over past year

View more statistics