进料方式对共沉淀法制备高温甲烷化催化剂性能的影响

摘要

以共沉淀法为基础,通过改变加料方式,制备了正加法、反加法及并流法的Ni-Mg-Al催化剂.采用N2低温吸附-脱附、XRD、H2-化学吸附和H2-TPR对催化剂进行表征,并将催化剂用于合成气甲烷化反应.结果表明,采用并流共沉淀法制备的催化剂,结晶度更为完整,形成了更为稳定的镍晶粒,孔结构分布均匀、同时活性组分与载体之间具有适宜的相互作用,使得催化剂具有优异的低温活性及高温稳定性.%Ni-Mg-Al catalysts were prepared by different precipitation methods:normal-precipation, reverse-precipitation and parallel-flow-precipitaion.The catalysts were characterized by N2-physi-sorption,XRD,H2-Chemsorption and H2-TPR and tested in syngas methanation.The results showed that catalysts prepared by parallel -flow -precipitation showed excellent low temperature activity and high temperature stability because of higher degree of crystallinity,more stable nickel grains,uniform pore distribution and appropriate interaction between active components and carries.