载体孔结构对镍基甲烷化催化剂催化活性的影响  

Effect of support structure on the catalytic activity of nickel-based methanation catalysts

作　　者：袁涌天 尹燕华[1] 周旭[1] 周军成[1] 

机构地区：[1]中国船舶重工集团公司第七一八研究所,河北邯郸056027

出　　处：《天然气化工—C1化学与化工》2015年第3期32-36,共5页Natural Gas Chemical Industry

摘　　要：利用两种比表面积、孔容与平均孔径相近,孔径分布明显不同的γ-Al2O3载体浸渍得到了两种不同的Ni/Al2O3甲烷化催化剂,并进行XRD、SEM和H2-TPR表征。通过活性评价实验发现,孔径分布更分散的A载体制备得到的催化剂具有更好的活性。通过N2吸附发现,A载体中孔径为10nm以上的孔道较多。XRD与SEM表征发现,这种结构更有利于活性组分进入到载体的孔道内,使活性组分更好地分散形成粒径较小的Ni O晶粒,有效减少了活性组分在载体表面的团聚。H2-TPR的实验结果表明,利用A载体制备得到的Ni/Al2O3催化剂中,固定态的γ-Ni O要明显多于B催化剂,这种形态的Ni O还原后形成的Ni0更难烧结与流失,能有效提高催化剂的高温活性与稳定性。Two different γ-Al2O3 supports with similar specific surface area, pore volume and pore diameter but different pore size distribution were used to prepare two Ni/Al2O3 methanation catalysts by impregnation method, and the catalysts were characterized by XRD, SEM and H2-TPR. The results of catalytic performance evaluation showed that catalyst Ni/Al2O3-A prepared by using the support with more dispersive distribution of pore size performed better activity. It was found by N2 adsorption characterization that there was a quantity of pore with diameter greater than 10nm in support A, and results of XRD and SEM indicated which made the active component more easy into the the pore channels of support, favoring the dispersion of active component to form finer NiO crystallines and inhibit the aggregation of NiO. Results of H2-TPR showed that there was more “fixed”γ-NiO in catalyst Ni/Al2O3-A, and the reduction product of the “fixed” γ-NiO was more difficult to sinter and detach from the support, which was beneficial for the activity and stability of catalyst.

关 键 词：载体结构 孔径分布 Γ-AL2O3 甲烷化 催化剂 

分 类 号：TQ032[化学工程]