等离子体技术对CO2甲烷化用Ni/SiO2催化剂的改性作用

采用浸渍法制备了Ni/SiO₂催化剂,应用等离子体技术对催化剂进行改性处理。以CO₂甲烷化为模型反应对催化剂进行活性评价,通过H₂程序升温还原(H₂-TPR)和CO₂程序升温脱附(CO₂-TPD)技术对催化剂进行表征。研究了等离子体技术强化处理对催化剂吸附性能和还原性能的影响。结果表明,与常规焙烧的催化剂相比,等离子体技术改性处理提高了催化剂活性组分的分散度,增加反应活性位并调变了活性位对吸附物种的吸附强度,改进了催化剂的还原性能,CO₂甲烷化反应活性和甲烷的时空产率显著提高。

Effect of glow discharge plasma treatment on the performance of Ni/SiO2 catalyst in CO2 methanation

Ni/SiO₂ catalysts were prepared by impregnation method and treated by glow discharge plasma. The Ni/SiO₂ catalysts were characterized by CO₂-TPD and H₂-TPR; the effects of plasma treatment on the performances of Ni/SiO₂ in adsorption, reduction, and catalytic methanation of CO₂ were investigated. The results showed that the plasma treatment can remarkably improve the dispersion of active components and enhance the reactivity of Ni/SiO₂ catalyst. The catalytic performance of Ni/SiO₂ in CO₂ methanation is also enhanced by the plasma treatment; the conversion of CO₂ and the space time yield of CH₄ over the plasma modified catalyst are higher than those over the Ni/SiO₂ catalyst obtained through conventional impregnation and calcination method.