IR study of alkene allylic activation on magnesium ferrite and alumina catalysts

DOI: 10.1039/ft9969204687

Source and publish data:

Journal of the Chemical Society - Faraday Transactions p. 4687 - 4694 (1996)

Update date:2022-08-11

Topics:

Authors:

Busca, Guido

Finocchio, Elisabetta

Lorenzelli, Vincenzo

Trombetta, Marcella

Rossini, Stefano A.

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Article abstract of DOI:10.1039/ft9969204687

The interaction of propene and butenes with oxydehydrogenation catalyst, MgFe2O4, and with an isomerization catalyst, γ-Al2O3, have been studied by FTIR spectroscopy.Allyloxy species (prop-2-en-1-oxides from propene and but-3-en-2-oxide from but-1-ene) were observed over MgFe2O4, while allyl species (prop-2-en-1-yl from propene, but-3-en-2-yl from but-1-ene and 2-methylprop-2-en-1-yl from isobutene), thought to be ?-bonded to Al³⁺ ions, were observed over γ-Al2O3.It is proposed that on all cases the allylic C-H bond is heterolytically broken at cation-anion couples (Mⁿ⁺O^2-) to give rise to anionic allyls.However, when the cation is reducible, as on the Fe³⁺ centers of magnesium ferrite, the allyl anion is further rapidly oxidized to allyloxy species that, at high temperature, can act as cationic allyls which interact weakly with oxide anions.From propene, the cationic allyls can act as symmetric species, as is expected for acrolein synthesis.