Journal of the Brazilian Chemical Society (Jan 2003)

Selective hydrogenation of 1,3-butadiene by transition metal compounds immobilized in 1-butyl-3-methyl imidazolium room temperature ionic liquids

  • Consorti Crestina S.,
  • Umpierre Alexandre P.,
  • Souza Roberto F. de,
  • Dupont Jairton,
  • Suarez Paulo A. Z.

Journal volume & issue
Vol. 14, no. 3
pp. 401 – 405

Abstract

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The compounds [Co(acac)2], [Co(acac)3], [Fe(acac)3] and [Ni(acac)2] (acac = acetylacetonate) dissolved in 1-butyl-3-methyl imidazolium tetrafluoroborate (1), trifluoromethanesulphonate (2) or hexafluorophosphate (3) catalyze the reduction of 1,3-butadiene into butenes in a typical two-phase catalytic reaction. The 1,3-butadiene conversion, the selectivity and turnover frequencies (TOF) are strongly dependent on the nature of the transition metal catalyst precursor and the ionic liquid. For [Co(acac)2] dissolved in 1, kinetic studies strongly suggest that the reaction takes place in the ionic solution bulk, having an apparent activation energy for the overall process of 33.8 kJ mol-1. The recovered ionic catalyst solution can be reused several times without any significant changes on activity and selectivity.

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