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    烯丙基聚醚异构化中 Speier 催化剂失活动力学建模

    Kinetic modeling of Speier catalyst deactivation in allyl polyether isomerization

    • 摘要: 为了定量描述Speier催化剂在烯丙基聚醚异构化反应中的失活行为,构建了耦合催化剂动态价态演变的反应动力学模型。通过实验揭示反应遵循Herzfeld-Laidler机理,并基于Pt(Ⅳ)→Pt(Ⅱ)→Pt(0)两步连续失活假设,将Van’t Hoff络合物与Arrhenius温度关系嵌入动力学方程,建立了包含催化剂失活的完整模型。利用不同温度(398-418 K)下的转化率-时间数据对模型进行全局拟合,结果表明,反应速率常数K为6.27 mol·L−1,最大反应速率活化能 E_a, \textxmax = 63.7 kJ·mol−1,Pt(Ⅱ)相对活性r2 = 0.307,模型决定系数R2 > 0.99。研究结论表明,Pt(Ⅳ)贡献了约98.9%的初始活性,高温同时促进异构化反应与催化剂失活;所建模型可为Speier催化剂设计及异构化工艺优化提供理论参考。

       

      Abstract: To quantitatively describe the deactivation behavior of the Speier catalyst during the isomerization of allyl polyethers, a reaction kinetic model coupled with the dynamic evolution of Pt valence states was developed. Experiments indicated that the reaction followed the Herzfeld-Laidler mechanism. Based on a two-step consecutive deactivation assumption, Pt(Ⅳ)→Pt(Ⅱ)→Pt(0), a kinetic equation incorporating the Van’t Hoff complex and Arrhenius temperature dependence was established. The model was globally fitted to conversion–time data at 398–418 K. The results showed that the reaction rate constant K was 6.27 mol·L1, the activation energy of maximum rate was 63.7 kJ·mol1, the relative activity of Pt(Ⅱ) was 0.307, and the coefficient of determination R2 exceeded 0.99. The results indicate that Pt(Ⅳ) contributes approximately 98.9% of the initial activity, and elevated temperature significantly promotes both isomerization and catalyst deactivation. The model provides a theoretical reference for Speier catalyst design and process optimization.

       

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