微燃烧法制备Ni/SiO2催化剂及燃料比例对催化剂结构和CO甲烷化性能的影响

Preparation of Ni/SiO2 catalyst via micro-combustion method and the effect of fuel ratio on its structure and catalytic property in CO methanation

采用介质阻挡放电等离子体(DBD)引发的微燃烧法制备了一系列Ni/SiO2催化剂,研究了燃料加入量对催化剂结构性能的影响,采用N2吸附-脱附、XRD、H2-TPR、H2-TPD和TEM对催化剂进行了表征,利用CO甲烷化反应对催化剂性能进行了测试。结果表明,随着燃料比例的增加,Ni/SiO2催化剂的催化活性和稳定性先升高后降低。当还原剂和氧化剂化合价之比为1.25时催化剂效果最好,在360℃,进料H2/CO体积比为3、空速60000mL/(g(cat)h)时,CO转化率达到97.7%,甲烷收率达到71.5%。高温稳定性考察反应6h,催化剂表现出良好的抗烧结性能。

A series of Ni/SiO2 catalysts were prepared by micro-combustion method initiated by dielectric barrier discharge(DBD)plasma.The effects of fuel addition on the structure and properties of the catalysts were studied.The catalysts were characterized by N2 adsorption desorption,XRD,H2-TPR,H2-TPD and TEM,and their catalytic properties in CO methanation were tested.The results showed that the catalytic activity and stability of the Ni/SiO2 catalyst were improved first and then decreased with the increase of fuel ratio.When the valence ratio of reducing agent to oxidant is 1.25,the prepared catalyst exhibited excellent catalytic activity.Under the reaction conditions of 360℃,H2/CO volume ratio of 3 in feed gas and space velocity of 60,000mL/(gcat h),the CO conversion reached to 97.7%with a methane yield of 71.5%.The catalyst showed good sintering resistance in the high-temperature stability test of 6 hours.