Decomposition of nitric oxide by rhodium cluster cations at high temperatures.
Phys Chem Chem Phys
; 23(47): 26721-26728, 2021 Dec 08.
Article
in En
| MEDLINE
| ID: mdl-34842875
ABSTRACT
Decomposition reactions of NO molecules on gas-phase Rhn+ (n = 6-9) clusters were investigated by gas-phase thermal desorption spectrometry and density functional theory calculations. We found that NO adsorbs on the clusters, forming RhnNxOx+ at room temperature. Upon heating, NO desorption was observed below 800 K. Above 800 K, while for n = 7 and 8, each of Rh7N3O3+, Rh7N4O4+, and Rh8N3O3+ was found to release an N2 molecule, no N2 formation was clearly observed for Rh6,9NxOy+. We considered that both Rh7N3O3+ and Rh8N3O3+ have at least two dissociated NO molecules, while Rh6NxOx+ (x = 1-3) has one or less. Our computational results for Rh8N3O3+ suggested that the formation of an N-N bond in the Rh8N3O3+ structure must overcome an energy barrier of â¼2 eV, which is the highest among the suggested possible reaction pathways. These findings suggested that the size-dependent activity of NO decomposition is governed primarily by how NO molecules are adsorbed on Rhn+ clusters, i.e. whether two or more N atoms from dissociated NO molecules exist in the NO adsorbed clusters, and secondly, by the readiness of the N-N bond formation.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Language:
En
Journal:
Phys Chem Chem Phys
Journal subject:
BIOFISICA
/
QUIMICA
Year:
2021
Document type:
Article
Affiliation country:
Japan