SCI和EI收录∣中国化工学会会刊

Chinese Journal of Chemical Engineering ›› 2014, Vol. 22 ›› Issue (5): 509-515.DOI: 10.1016/S1004-9541(14)60071-9

• 催化、动力学与反应工程 • 上一篇    下一篇

Effects of Oxygen Transfer Limitation and Kinetic Control on Biomimetic Catalytic Oxidation of Toluene

罗伟平, 刘大为, 孙俊, 邓伟, 盛文兵, 刘强, 郭灿城   

  1. College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, China
  • 收稿日期:2012-10-30 修回日期:2013-08-10 出版日期:2014-05-28 发布日期:2014-05-06
  • 通讯作者: GUO Cancheng,E-mail: ccguo@hnu.edu.cn
  • 基金资助:

    Supported by the Fundamental Research Funds for the Central Universities, Ministry of Education, China.

Effects of Oxygen Transfer Limitation and Kinetic Control on Biomimetic Catalytic Oxidation of Toluene

LUO Weiping, LIU Dawei, SUN Jun, DENG Wei, SHENG Wenbing, LIU Qiang, GUO Cancheng   

  1. College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, China
  • Received:2012-10-30 Revised:2013-08-10 Online:2014-05-28 Published:2014-05-06
  • Supported by:

    Supported by the Fundamental Research Funds for the Central Universities, Ministry of Education, China.

摘要: Under oxygen transfer limitation and kinetic control, liquid-phase catalytic oxidation of toluene over metalloporphyrin was studied. An improved technique of measuring dissolved oxygen levels for gas-liquid reaction at the elevated temperature and pressure was used to take the sequential data in the oxidation of toluene catalyzed by metalloporphyrin. By this technique the corresponding control step of toluene oxidation could be obtained by varying reaction conditions. When the partial pressure of oxygen in the feed is lower than or equal to 0.070 MPa at 463 K, the oxidation of toluene would be controlled by oxygen transfer, otherwise the reaction would be controlled by kinetics. The effects of both oxygen transfer and kinetic control on the toluene conversion and the selectivity of benzaldehyde and benzyl alcohol in biomimetic catalytic oxidation of toluene were systematically investigated. Three conclusions have been made from the experimental results. Firstly, under the oxygen transfer limitation the toluene conversion is lower than that under kinetic control at the same oxidation conditions. Secondly, under the oxygen transfer limitation the total selectivity of benzaldehyde and benzyl alcohol is lower than that under kinetic control with the same conversion of toluene. Finally, under the kinetics control the oxidation rate of toluene is zero-order with respect to oxygen. The experimental results are identical with the biomimetic catalytic mechanism of toluene oxidation over metalloporphyrins.

关键词: kinetic control, oxygen transfer limitations, catalysis, toluene, oxidation, porphyrin

Abstract: Under oxygen transfer limitation and kinetic control, liquid-phase catalytic oxidation of toluene over metalloporphyrin was studied. An improved technique of measuring dissolved oxygen levels for gas-liquid reaction at the elevated temperature and pressure was used to take the sequential data in the oxidation of toluene catalyzed by metalloporphyrin. By this technique the corresponding control step of toluene oxidation could be obtained by varying reaction conditions. When the partial pressure of oxygen in the feed is lower than or equal to 0.070 MPa at 463 K, the oxidation of toluene would be controlled by oxygen transfer, otherwise the reaction would be controlled by kinetics. The effects of both oxygen transfer and kinetic control on the toluene conversion and the selectivity of benzaldehyde and benzyl alcohol in biomimetic catalytic oxidation of toluene were systematically investigated. Three conclusions have been made from the experimental results. Firstly, under the oxygen transfer limitation the toluene conversion is lower than that under kinetic control at the same oxidation conditions. Secondly, under the oxygen transfer limitation the total selectivity of benzaldehyde and benzyl alcohol is lower than that under kinetic control with the same conversion of toluene. Finally, under the kinetics control the oxidation rate of toluene is zero-order with respect to oxygen. The experimental results are identical with the biomimetic catalytic mechanism of toluene oxidation over metalloporphyrins.

Key words: kinetic control, oxygen transfer limitations, catalysis, toluene, oxidation, porphyrin