正交多项式曲线拟合法对变温相转移催化的动力学研究

A STUDY OF NON-ISOTHERMAL CATALYTIC KINETICS OF PHASE TRANSFER BY ORTHOGONAL POLYNOMIAL CURVE FITTING

本文利用正交多项式对浓度函数与时间进行曲线拟合,研究相转移试剂四丁基硫酸氢铵(Bu_4NHSO_4)存在下,K_2Cr_2O_7在5mol·l^(-1)H_2SO_4介质中氧化对二甲苯,生成对二苯甲酸的变温动力学过程。研究结果表明,正交多项式曲线拟合法研究变温相转移催化动力学实验速度快、计算简便、计算误差小。此法是一种准确、快速、可靠的研究方法。

A study was made of the non-isothermal catalytic kinetics of phase transfer of xylene into toluic acid with Bu_4NHSO_4 as a phase transfer agent and 0,05 mol/L K_2Cr_2O_7 in 5 mol/L H_2SO_4 as an oxidizing agent. The relationship between concentration and time was ascertained by orthogonal polynomial curve fitting. And the kinetics parameters(rate constants at different temperatures and activation energy)were obtained. The results show that non-isothermal kinetics method is faster than isothermal kinetics method when on the same accuracy level and the former has two main advantages over the latter. First, it can reduce orders of polynomial and a lot of calculation. Second, it can avoid ill-conditions in polynomial curve fitting, and hence calculation error. The results also show that using orthogonal polynomial curve fitting to study non-isothermal phase transfer catalytic kinetics is convient, accurate and reliable.