二氧化碳加氢甲烷化镍锰基催化剂的研究

研究了锰组分的添加含量及制备方法对Ni/g-Al2O3催化剂上二氧化碳加氢合成甲烷的影响,并用XRD,TPR,BET等手段进行表征。研究结果表明,在常压、400℃、n(H2):n(CO2)=4:1、空速为6000h-1条件下,采用共浸渍法制备Mn-Ni/g-Al2O3催化剂,n(Mn):n(Ni)=1:2时催化剂活性达到最高,CO2转化率达到77.92%,甲烷选择性超过96%。表征结果显示,添加的锰组分较好地分布在催化剂表面,并使镍晶粒细化,增强了镍物种与载体的相互作用,催化剂更易于还原,催化活性显著提高。

Study on Ni-Mn-based catalysts for methanation of carbon dioxide

Effects of Mn promoter amounts and preparation methods on the activity of Ni/γ-Al2O3 catalysts for CO2 methanation by hydrogenation were studied,and the catalysts were characterized by TPR,XRD and BET.The results showed that under the reaction conditions of atmospheric pressure,400℃,GHSV=6000h-1 and n(H2)∶n(CO2)=4∶1,the Mn-Ni/γ-Al2O3 catalyst with Mn/Ni atomic ratio of 1∶2 prepared by Mn-Ni co-impregnation displayed the highest activity,over which the conversion of CO2 reached 77.92% and the selectivity to methane was over 96%.The results of catalyst characterization indicated that Mn promoter was well dispersed on the surface of γ-Al2O2 that could significantly reduce the particle size of nickel crystallites and improve the interaction between nickel species and the support,which resulted that the catalyst was more easily reduced and exhibited significantly enhanced activity.