Abstract: The kinetics of trace Ir(III) catalyzed oxidation of tetrahydrofurfuryl alcohol(THFA) by Ce(IV) in aqueous sulphuric acid medium was studied by titrimetric technique of redox in the temperature range of 298~313 K. The order was found to be unity with respect to both Ce(IV) and Ir(III), and for tetrahydrofurfuryl alcohol the apparent reaction order was a positive fraction. It was found that the pseudo first order ([THFA]>>[Ce(IV)]) rate constant, kobs, increased with the increase of [H＋] but decreased with the increase of [HSO₄－]. Under the protection of nitrogen, however, the reaction system could induce polymerization of acrylonitrile, indicating the generation of free radicals. A reasonable mechanism involving a preequilibrium was proposed. From the relation between kobs and [HSO₄－], Ce(SO₄)₂ was found to be the kinetically active species. The equilibrium constants and rate constants of the rate-determining step along with the activation parameters were evaluated.

Key words: Iridium(III) ion, Cerium(IV) ion, Tetrahydrofurfuryl alcohol, Catalyst, Kinetics, Mechanism