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Title
  • en Selective hydrogenation of nitrostyrene to aminostyrene over Pt/TiO2 catalysts : Effects of pressurized carbon dioxide and catalyst preparation conditions
Creator
Accessrights open access
Subject
  • Other en Carbon dioxide
  • Other en Hydrogenation
  • Other en Platinum catalyst
  • Other en Molecular interaction
  • Other en SMSI
  • NDC 571
Description
  • Abstract en The present work has studied the influence of CO2 pressurization on the hydrogenation of nitrostyrene (NS) using Pt/TiO2. With CO2 pressurization up to 12 MPa (CO2-dissolved expanded liquid (CXL) phase), the over-all reaction rate and the selectivity to aminostyrene (AS) increased. At higher CO2 pressures where all NB dissolved in scCO2 (scCO2-homogeneous phase), both of them decreased with increasing the CO2 pressure. The phase behavior was an important factor for the present reaction system. It was also found that the presence of pressurized CO2 gave higher selectivity to AS than in its absence at any conversion level. This was ascribed to retardation effects of dense phase CO2 on the hydrogenation of AS to ethylaniline. Competitive adsorption of nitro and vinyl groups was suggested to determine the product selectivity. FTIR measurements showed that the pressurized CO2 lowers the reactivity of the nitro group, and this effect is stronger in scCO2-homogeneous phase than in CXL phase, resulting in the lower AS selectivity in the former phase. Lower Pt loadings and higher catalyst reduction temperatures gave Pt/TiO2 catalysts more selective for the AS formation. FTIR measurements of adsorbed CO over the catalysts suggested that the presence of less-coordinated Pt atoms on edge, corner and kink sites was significant for the selective hydrogenation of NS to AS.
Publisher en Elsevier B.V.
Date
    Issued2011-12
Language
  • eng
Resource Type journal article
Version Type AM
Identifier HDL http://hdl.handle.net/2115/48154
Relation
  • isVersionOf DOI https://doi.org/10.1016/j.supflu.2011.02.016
Journal
    • PISSN 0896-8446
      • en The Journal of Supercritical Fluids
      • Volume Number60 Page Start106 Page End112
File
Oaidate 2023-07-26