二氧化碳甲烷化反应中等离子体与rNi/ZSM-5催化剂的协同作用

摘要

在介质阻挡放电等离子体反应器中研究了等离子体对Ni/ZSM-5催化剂催化CO2甲烷化反应的促进作用,采用XRD和低温N2吸附-脱附对Ni/ZSM-5催化剂进行了表征,考察了催化剂原位还原条件和反应条件对催化剂性质和反应性能的影响.实验结果表明,采用氢等离子体法可将催化剂前体转化为高分散、高活性的Ni/ZSM-5催化剂,等离子体还原时存在一个最佳输入功率.催化剂与等离子体具有显著的协同作用,在输入功率为33.3 W、原料气n(H):n(C)=5、气态空速为3600 h-1的条件下,CO2转化率可达98％,甲烷选择性接近100％.%The promoting effects of the non-thermal plasma in Ni/ZSM-5-catalyzed methanation of CO2 were investigated in a dielectric barrier discharge reactor. Ni/ZSM-5 catalyst was prepared in situ from NiO/ZSM-5 by H2 plasma reduction and characterized by XRD and N2 adsorption-desorption. The reduction and reaction conditions were optimized. It is shown that highly dispersed Ni particles on ZSM-5 were obtained by the H2plasma reduction method. A significant synergetic effect was observed for the non-thermal plasma and Ni/ZSM-5 in CO2methanation. A conversion of 98％ with selectivity to methane of around 100％ was achieved at the following reaction conditions:input power 33.3 W, n(H):n(C) 5,GHSV 3600 h-1.