Kinetics and mechanism of ruthenium(III) catalyzed oxidation of tetrahydrofurfuryl alcohol by cerium(IV) in sulfuric acid media

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• 作者：Yongqing Zhai ; Hongmei Liu ; Baosheng Liu ; Yukai Liu ; Jia Xiao and Weisong Bai
• 刊名：Transition Metal Chemistry
• 出版年：2007
• 出版时间：August, 2007
• 年：2007
• 卷：32
• 期：5
• 页码：570-575
• 全文大小：355 KB

文摘

The kinetics and mechanism of ruthenium(III) catalyzed oxidation of tetrahydrofurfuryl alcohol (THFA) by cerium(IV) in sulfuric acid media have been investigated spectrophotometrically in the temperature range 298–313 K. It is found that the reaction is first-order with respect to CeIV, and exhibits a positive fractional order with respect to THFA and RuIII. The pseudo first-order ([THFA]≫[CeIV]≫[RuIII]) rate constant k _obs decreases with the increase of [HSO ₄ − ]. Under the protection of nitrogen, the reaction system can initiate polymerization of acrylonitrile, indicating the generation of free radicals. On the basis of the experimental results, a reasonable mechanism has been proposed and the rate equations derived from the mechanism can explain all the experimental results. From the dependence of k _obs on the concentration of HSO ₄ − , Ce(SO₄)₂{{\rm Ce}({\rm SO}_{4})_{2}} has been found as the kinetically active species. Furthermore, the rate constants of the rate determining step together with the activation parameters were evaluated.