We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
Effect of Crystallographic Phase (β vs. γ) and Surface Area on Gas Phase Nitroarene Hydrogenation Over MoN and Au/MoN.
- Authors
Perret, Noémie; Cárdenas-Lizana, Fernando; Lamey, Daniel; Laporte, Vincent; Kiwi-Minsker, Lioubov; Keane, Mark
- Abstract
The catalytic action of MoN and Au/MoN has been assessed in the selective gas phase hydrogenation of p-chloronitrobenzene ( p-CNB) to p-chloroaniline ( p-CAN). The nitrides were synthesised via temperature programmed treatment of MoO in H + N and Au introduced by deposition-precipitation with urea. We have examined the influence of nitride crystallographic phase (tetragonal β-MoN vs. cubic γ-MoN) and surface area (7-66 m g) on the catalytic response. Catalyst activation by temperature programmed reduction has been monitored and the reduced catalysts characterised in terms of BET area/pore volume, H chemisorption/temperature programmed desorption (TPD), powder X-ray diffraction (XRD), elemental analysis, scanning (SEM) and transmission (TEM) electron microscopy and X-ray photoelectron spectroscopy (XPS) measurements. The formation of β- and γ-MoN was confirmed by XRD and TEM. γ-MoN exhibits a platelet morphology whereas β-MoN is characterised by an aggregation of small crystallites. Hydrogen chemisorption and TPD analysis have established a greater hydrogen uptake capacity (per unit area) for β-MoN relative to γ-MoN, which is associated with surface nitrogen deficiency, i.e. higher surface Mo/N for β-MoN. Incorporation of Au on both nitrides resulted in an increase in surface hydrogen. The Au phase takes the form of nano-scale particles with a mean size of 7 and 4 nm on β-MoN and γ-MoN, respectively. Both β-MoN and γ-MoN promoted the exclusive hydrogenation of p-CNB to p-CAN where the β-form delivered a higher specific (per m) rate; the specific rate for γ-MoN was independent of surface area. The inclusion of Au on both nitrides served to enhance p-CAN production.
- Subjects
CRYSTALLOGRAPHY; SURFACE area; GAS phase reactions; NITROAROMATIC compounds; HYDROGENATION; GOLD catalysts; MOLYBDENUM nitrides; CHLORONITROBENZENES
- Publication
Topics in Catalysis, 2012, Vol 55, Issue 14/15, p955
- ISSN
1022-5528
- Publication type
Article
- DOI
10.1007/s11244-012-9881-4