镍盐前体对Ni-Fe/γ-Al2O3催化剂甲烷化性能的影响

摘要

以3种不同镍盐（硝酸镍、乙酸镍和氯化镍）为前体，采用等体积浸渍法制备了双金属 Ni-Fe/γ-Al2O3催化剂，分别记作Ni-Fe-N、Ni-Fe-Ac和Ni-Fe-Cl，在浆态床反应装置上对各催化剂CO甲烷化催化活性进行评价。结果表明，Ni-Fe-N甲烷化催化活性最高，CO转化率、CH4选择性分别为97.2%和87.3%；而Ni-Fe-Cl甲烷化催化活性最低，CO转化率、CH4选择性分别为47.3%和58.7%。通过XRD、H2-TPR和CO-TPD等表征技术探讨了催化剂的微观结构与甲烷化催化活性之间的关系，发现 Ni-Fe-N 甲烷化活性高的原因是 NiO 晶粒小、分散好，Ni与Fe之间具有较好的协同作用，并且CO吸附量大。%Bimetallic Ni-Fe/γ-Al2O3 catalysts were prepared from different nickel precursors of Ni(NO3)2,Ni(CH3CO2)2 and NiCl2 (denoted as Ni-Fe-N,Ni-Fe-Ac,Ni-Fe-Cl,respectively) by the impregnation method. The catalysts for CO methanation in a slurry-bed reactor were investigated using XRD,CO-TPD and H2-TPR. Ni-Fe-N showed maximal catalytic activity for CO methanation,with CO conversion of 97.2% and CH4 selectivity of 87.3%,while Ni-Fe-Cl showed a minimum activity with CO conversion of 47.3% and CH4 selectivity of 58.7%. The higher activity of Ni-Fe-N was attributed to high dispersion of NiO,interaction between Ni and Fe in bimetallic catalyst and high adsorption capacity for CO.