载体酸碱性对CO2／CH4重整反应用镍基催化剂的影响

Effect of Support Basicity on the Performance of Ni-based Catalyst for Carbon Dioxide Reforming Methane

考察了6种载体对镍基催化剂的CO2/CH4重整反应性能的影响,并采用CO2-TPD,H2-TPR和BET技术对催化剂进行表征。结果表明,Ni/MgO-Al2O3催化剂表现出较好催化活性和较高的反应产率,且反应后催化剂的失活率最小(4.65%)。载体的酸碱性和比表面积的大小直接影响到催化剂的反应性能,经碱土金属修饰的复合载体表面的碱性增强,提高了对CO2的吸附解离能力,使催化剂在重整反应中表现出较好的抗积炭能力。各催化剂的稳定性依次为:Ni/MgO-Al2O3>Ni/MCM-41>Ni/MgO>Ni/Al2O3>Ni/ZrO2>Ni/ZSM-5。

The effects of different supports on the catalytic performances of Ni-based catalysts for CO2 reforming CH4 reaction were investigated. The results indicated that the catalyst prepared by MgO- modified A1203 support possessed higher activities and lower deactivation rate than other supported catalysts. The performance of Ni-based catalyst was affected by the basicity and specific surface area of a support. Doping Mg on the support was benefit to increase the adsorption of CO2, which could decrease the formation of coke. The stability order of the various catalysts is： Ni/MgO-Al2O3 〉 Ni/ MCM-41 〉 Ni/MgO 〉 Ni/Al2O3 〉 Ni/ZrO2 〉 Ni/ZSM-5.