VPO催化剂再生动力学特性研究

Reoxidation kinetic characteristics of the VPO catalyst

利用热分析技术研究了流动气氛下VPO催化剂再氧化的反应行为及非等温反应动力学,采用几种不同的方法处理实验数据均得到较一致的结果,据此推断VPO催化剂最可几的氧化再生机理符合相边界控制的收缩核模型,得到了动力学方程为dα/dt=Aexp（-E/RT）×3（1-α）2/3,活化能E-238.57kJ/mol,指前因子A=7.74×1013s-1。

DTA, TG and DTG techniques were used to investigate the thermal oxidation process and reaction kinetics of a domestic VPO catalyst at the heating rate of 2.5、5、10 and 20 K/min in the air, respectively. Several methods for estimating the kinetic parameters and identifying the mechanism of the reaction-diffusion process were compared, and used to treat the non-isothermal kinetic data. The results obtained suggest that the reoxida-tion process of the catalyst obeys the contracted core model controlled by the phase border. The reaction rate equation can be expressed as da/dt = Aexp(-E/RT)×(1-α)2/3 , where the activation energy E = 238.57 kJ/mol, the frequency factor A =7.74×1013 s-1.