铯-铷-钒系低温硫酸催化剂上SO_2氧化反应速率的机理解释

STUDY ON THE MECHANISM FOR THE LOW TEMPERATURE SO_2 OXIDATION WITH Cs-Rb-V SULFURIC ACID CATALYST

以碱金属盐为助催化剂的铯 -铷 -钒系硫酸催化剂 ,在 380～ 5 2 0℃下 SO2 氧化反应机理为三步催化反应 ,并推导出其动力学机理模型 :r=k1P1/ 2O2k2 +k3 PSO3 +PSO3 PSO2(1- PSO3 PSO2 P1/ 2O2 KP)。采用内循环无梯度反应器测定了SO2 氧化反应动力学数据 ,并利用 Powell法对动力学模型进行参数估值 ,得到 :k1=0 .15 2 exp(- 6 2 0 73/ RT) ,k2 =8.18exp(- 2 384/ RT) ,k3 =0 .2 2 1exp(- 18949/ RT)。方差分析表明 ,在显著性水平 0 .0 1下 ,三步反应机理模型对反应速率实验值拟合较好 ,标准偏差为 0 .2

A three-step reaction mechanism for SO2 oxidation on Cs-Rb-V low temperature sulfuric acid catalyst promoted by mixture of alkali salts was proposed. A kinetic equation was derived as follows: r=k1PO(2)1/2/k2+k3 PSO(3)+PSO(3)/PSO(2)(1-PSO(3) /PSO(2)PO(2)1/2Kp). The kinetic data was measured with a non-gradient reactor, The parameters of the model equation were calculated based on experimental results by the Powell non-linear regression method: k1=0.152e-62073/RT, k2=8.18e-2384/RT, k3=0.221e-18949/RT. The model equation fitted the rate data well and the standard deviation was less than 0.242.