Advanced

Isokinetic behavior in the gas phase hydrogenation of nitroarenes over Au/TiO2: application of the selective energy transfer model

Keane, Mark A. and Larsson, Ragnar LU (2012) In Reaction Kinetics, Mechanisms and Catalysis 106(2). p.267-288
Abstract
The gas phase selective hydrogenation of a series of nitroarenes (nitrobenzene, p-chloronitrobenzene, p-bromonitrobenzene, p-nitroaniline, p-nitrotoluene, p-nitrophenol and p-nitroanisole) has been examined over Au/TiO2 (0.3 % w/w Au, mean Au particle size = 3.9 nm). Compensation behavior is demonstrated with an associated isokinetic temperature (T-iso) of 558 +/- 32 K. We account for this response in terms of the selective energy transfer (SET) model where the occurrence of resonance between catalyst and reactant vibrations generates the activated complex. An analysis of the stepwise variation of the activation energies has identified a critical vibrational frequency of 853 cm(-1), which is close (+/- 2 cm(-1)) to the reference value for... (More)
The gas phase selective hydrogenation of a series of nitroarenes (nitrobenzene, p-chloronitrobenzene, p-bromonitrobenzene, p-nitroaniline, p-nitrotoluene, p-nitrophenol and p-nitroanisole) has been examined over Au/TiO2 (0.3 % w/w Au, mean Au particle size = 3.9 nm). Compensation behavior is demonstrated with an associated isokinetic temperature (T-iso) of 558 +/- 32 K. We account for this response in terms of the selective energy transfer (SET) model where the occurrence of resonance between catalyst and reactant vibrations generates the activated complex. An analysis of the stepwise variation of the activation energies has identified a critical vibrational frequency of 853 cm(-1), which is close (+/- 2 cm(-1)) to the reference value for nitro-group (in-plane symmetric O-N-O bending and stretching) vibrations. Application of SET suggests activation of weakly adsorbed nitroarene (at the support or metal/support interface) by excitation of the nitro-group via IR radiation from a strongly adsorbed surface nitroarene component. The excited nitroarene is then attacked by reactive hydrogen supplied by the Au sites to generate the respective aromatic amine with 100 % selectivity. Agreement of the SET predicted T-iso with the experimental value requires the incorporation of a term due to C-N torsional entropy resulting from distortion of the O-N-O plane. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Isokinetic temperature, Compensation behavior, Selective energy transfer, model, Catalytic hydrogenation, Nitroarenes, Au/TiO2
in
Reaction Kinetics, Mechanisms and Catalysis
volume
106
issue
2
pages
267 - 288
publisher
Springer
external identifiers
  • wos:000306193700002
  • scopus:84864619274
ISSN
1878-5204
DOI
10.1007/s11144-012-0440-6
language
English
LU publication?
yes
id
80b00bcf-4501-43cd-b776-23a714de87e2 (old id 2994944)
date added to LUP
2012-08-21 15:39:28
date last changed
2017-01-15 03:09:01
@article{80b00bcf-4501-43cd-b776-23a714de87e2,
  abstract     = {The gas phase selective hydrogenation of a series of nitroarenes (nitrobenzene, p-chloronitrobenzene, p-bromonitrobenzene, p-nitroaniline, p-nitrotoluene, p-nitrophenol and p-nitroanisole) has been examined over Au/TiO2 (0.3 % w/w Au, mean Au particle size = 3.9 nm). Compensation behavior is demonstrated with an associated isokinetic temperature (T-iso) of 558 +/- 32 K. We account for this response in terms of the selective energy transfer (SET) model where the occurrence of resonance between catalyst and reactant vibrations generates the activated complex. An analysis of the stepwise variation of the activation energies has identified a critical vibrational frequency of 853 cm(-1), which is close (+/- 2 cm(-1)) to the reference value for nitro-group (in-plane symmetric O-N-O bending and stretching) vibrations. Application of SET suggests activation of weakly adsorbed nitroarene (at the support or metal/support interface) by excitation of the nitro-group via IR radiation from a strongly adsorbed surface nitroarene component. The excited nitroarene is then attacked by reactive hydrogen supplied by the Au sites to generate the respective aromatic amine with 100 % selectivity. Agreement of the SET predicted T-iso with the experimental value requires the incorporation of a term due to C-N torsional entropy resulting from distortion of the O-N-O plane.},
  author       = {Keane, Mark A. and Larsson, Ragnar},
  issn         = {1878-5204},
  keyword      = {Isokinetic temperature,Compensation behavior,Selective energy transfer,model,Catalytic hydrogenation,Nitroarenes,Au/TiO2},
  language     = {eng},
  number       = {2},
  pages        = {267--288},
  publisher    = {Springer},
  series       = {Reaction Kinetics, Mechanisms and Catalysis},
  title        = {Isokinetic behavior in the gas phase hydrogenation of nitroarenes over Au/TiO2: application of the selective energy transfer model},
  url          = {http://dx.doi.org/10.1007/s11144-012-0440-6},
  volume       = {106},
  year         = {2012},
}