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Increased thermal stability of activated N2 adsorbed on K-promoted Ni{110}

Accepted version
Peer-reviewed

Type

Article

Change log

Authors

Jenkins, SJ 
Liu, T 
Temprano, I 

Abstract

Industrial synthesis of ammonia takes place at high temperatures and pressures via the dissociative adsorption of molecular nitrogen on a transition metal catalyst. In contrast, biological ammonia synthesis occurs under ambient conditions via the hydrogenation of intact molecular nitrogen at the active site of an enzyme. We hypothesise that the latter process may be mimicked within an inorganic system if the intact nitrogen molecule can be polarised, rendering it particularly susceptible to attack by hydrogen. Furthermore, by analogy with the surface chemistry of carbon monoxide at alkali-modified nickel and cobalt surfaces, we consider whether such a polarisation may be achieved by coadsorption with potassium on the same or similar transition metals. Here, we report on reflection absorption infrared spectroscopy results, interpreted with the aid of first-principles density functional calculations, which reveal both similarities and differences between the behaviour of carbon monoxide and nitrogen. Importantly, our calculations suggest that the surface-induced dipole of molecular nitrogen can indeed be enhanced by the coadsorbed alkali metal.

Description

Keywords

0306 Physical Chemistry (incl. Structural)

Journal Title

Physical Chemistry Chemical Physics

Conference Name

Journal ISSN

1463-9076
1463-9084

Volume Title

Publisher

RSC