等离子体催化重整CH_(4)/CO_(2)中的等离子体强化表面反应动力学研究

Kinetic Investigation of Plasma-Enhanced Surface Reaction in Plasma Catalytic CH_(4)/CO_(2)Reforming

采用实验测量和模拟预测相结合的方法,通过构建详细的机理并开展零维动力学模拟,研究等离子体催化CH_(4)/CO_(2)重整过程中等离子体活性物质对表面反应动力学的强化效应。结果表明:等离子体与催化剂的协同对CH_(4)和CO_(2)的活化转化能力远强于纯等离子体;动力学模型对反应物的消耗和产物的生成具有较好的预测能力;活性自由基与吸附态物质之间的E-R反应具有较高的反应活性,能有效改变并促进表面反应路径,如等离子体强化的E-R反应CH_(3)(s)+O→CH_(3)O(s)的速率比相应的吸附态物质之间的L-H反应CH_(3)(s)+O(s)→CH_(3)O(s)+Ni(s)的速率高4个数量级;等离子体催化CH_(4)/CO_(2)重整过程中的表面反应路径主要以气相物质与表面吸附态物质之间的E-R反应为主。

Based on the combined use of experimental measurement and simulation prediction,the enhancement effect of plasma active substances on surface reaction kinetics in plasma catalytic CH_(4)/CO_(2)reforming was investigated by developing a detailed mechanism and conducting a zero-dimensional kinetic simulation.The results show that the coupling of catalyst with plasma is much more effective in CH_(4)and CO_(2)activation and conversion than plasma alone.The consumption of reactants and formation of products can be well predicted by the kinetic model.The E-R reaction between living free radicals and adsorbed-state substances has a high reactivity,which can effectively change and promote the surface reaction path.For example,the rate of plasma-enhanced E-R reaction CH_(3)(s)+O→CH_(3)O(s)is four orders of magnitude higher than that of L-H reaction CH_(3)(s)+O(s)→CH_(3)O(s)+Ni(s)between corresponding adsorbed-state substances.The surface reaction path is mainly dominated by E-R reaction between surface-adsorbed and gas-phase substances in plasma catalytic CH_(4)/CO_(2)reforming.