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·L
−1, the activation energy of maximum rate was 63.7 kJ·mol
−1, the relative activity of Pt(Ⅱ) was 0.307, and the coefficient of determination R
2 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.