乙醇在Pt/ZSM-5上催化氧化动力学

Kinetics of ethanol oxidation over Pt/ZSM-5 catalyst

在内径为4 mm的石英管燃烧器中进行了富氧条件下乙醇在Pt/ZSM-5上的催化深度氧化动力学实验,反应温度控制在428 K以下,建立了Power-rate law模型和Langmuir-Hinshelwood模型来表征乙醇的低温深度氧化反应,Power-rate law模型和Langmuir-Hinshelwood模型的活化能分别为95.96和103.72 kJ·mol^(-1),乙醇和氧气的反应级数分别为0.38和1.38。Langmuir-Hinshelwood模型中,乙醇的吸附常数比氧气的吸附常数大,说明乙醇在催化剂表面的吸附能力比氧气强,提高氧气的浓度比提高乙醇的浓度更有利于提高反应速率,这一点同样反映在氧气的反应级数比乙醇的反应级数大。

The kinetics of ethanol deep oxidation over Pt/ZSM-5 catalyst was carried out under oxygen-rich conditions in a quartz tube burner with an inner diameter of 4 mm.The reaction temperature was controlled below 428 K.The Power-rate law model and the Langmuir-Hinshelwood model are established to characterize the ethanol deep oxidation for the low-temperature.The activation energy catalytic oxidation is 95.96 and 103.72 kJ·mol?1 for the Power-rate law model and the Langmuir-Hinshelwood model respectively.The order of reaction for ethanol and oxygen is 0.38 and 1.38 respectively.In the Langmuir-Hinshelwood model,the adsorption constant of ethonal is larger than oxygen,indicating that the ethanol adsorption capacity of the catalyst surface is stronger than oxygen.Increasing the concentration of oxygen concentration is more conducive to increasing the reaction rate than ethanol,which is also reflected in the reaction order of oxygen is larger than ethanol.