Optimizing Nitrogen Reduction Reaction on Nitrides: A Computational Study on Crystallographic Orientation

• Published in: Topics in catalysis Vol. 65; no. 1-4; pp. 252 - 261
• Main Authors: Gudmundsson, Matthías, Ellingsson, Viktor, Skúlason, Egill, Abghoui, Younes
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.02.2022; Springer Nature B.V
• Subjects: Activation energy; Ammonia; Catalysis; Catalysts; Catalytic activity; Characterization and Evaluation of Materials; Chemical reduction; Chemistry; Chemistry and Materials Science; Crystallography; Density functional theory; Haber Bosch process; Industrial Chemistry/Chemical Engineering; Metal nitrides; Nitrogen; Orientation; Original Paper; Pharmacy; Physical Chemistry; Transition metals; Mars-van Krevelen mechanism; Crystallographic orientation; Electrochemical catalyst; Nitrogen reduction reaction; Density functional theory calculations; Transition metal nitrides
• ISSN: 1022-5528; 1572-9028
• DOI: 10.1007/s11244-021-01485-2

Pursuing an environmentally friendly alternative to the Haber–Bosch process, using density functional theory (DFT) we explore further the merit of transition metal nitride (TMN) surfaces as catalysts for the nitrogen reduction reaction (NRR). Prior studies by our group have investigated the (100) and (111) facets of these TMNs and found the (100) to be favored in all cases. Many of the (100) facets of TMNs showed promising activity for ammonia (NH 3 ) formation. Recent experiments investigating the polycrystalline growth of these TMNs indicated the substantial presence of the (110) facet as well, and so we explore the properties of this surface orientation and compare it to the (100) facets previously reported. The only (110) facets of TMN that showed any promise was VN, but it suffered from high activation energies for N 2 adsorption compared to the activation energy of N migration from the bulk, which would likely lead to decomposition of the catalyst. The (110) facets showed overall worse catalytic activity than the (100). The most important outcome of this study is that the presence of the (110) facet of these TMNs in the catalyst structure will be detrimental to the activity of the catalyst. Great care must be taken when investigating the performance of these catalysts by engineering the surface to only include the surface orientation of interest.