焙烧温度对Ni-Al_2O_3甲烷化催化剂性能的影响  

Effects of Calcination Temperature on the Catalytic Performance of Ni-Al_2O_3 Catalyst

作　　者：秦志峰[1] 任军[1] 苗茂谦[1] 谢克昌[1] 

机构地区：[1]太原理工大学煤科学与技术教育部和山西省重点实验室,太原030024

出　　处：《太原理工大学学报》2015年第4期394-398,共5页Journal of Taiyuan University of Technology

基　　金：国家自然科学基金资助项目:碳包覆铜纳米粒子限域型催化剂的构建及其性能研究(21376159);山西省科技攻关计划(20120313005-1)

摘　　要：以偏铝酸钠和硝酸镍为原料,采用均匀沉淀法制备出Ni质量分数为40%的Ni-Al2O3催化剂,考察了不同焙烧温度(350,450,550,650,750℃)下制备的催化剂在CO甲烷化反应中的催化活性,使用TG-DTG、N2吸附、XRD、H2-TPR和H2化学吸附分析了催化剂的织构、晶相和活性金属的化学形态。结果表明,随着焙烧温度的上升,Ni与Al2O3载体之间的相互作用逐渐变强,形成大量的NiAl2O4,在450℃焙烧的催化剂活性最佳,在压力1.0 MPa、空速20 000mL/(g·h)和温度220℃的反应条件下,CO转化率达到99%以上;随着焙烧温度的增加,催化剂活性与镍的活性比表面积变化趋势一致,先增加、后降低,表明催化剂镍的活性比表面积影响其活性。A series of Ni-Al2O3 catalysts were prepared using sodium aluminate and nickel ni- trate as raw materials through a homogeneous precipitation method. The effects of the calcination temperature （350, 450, 550, 650,750 ℃） on the catalytic performance of CO methanation were investigated, and the texture, crystalline phase and chemical form of active metals were charac- terized with the assistance of TG-DTG, BET, XRD, H2-TPR and H2 chemical adsorption tech- niques. The results show that with the increase of calcination temperature, the interaction be- tween Ni and Al2O3 is enhanced gradually so that large amount of NiAl2O4 is formed. By compar- ison,the 40NiAl-450 catalyst shows the optimal catalytic activity of above 99% CO conversion in the following operating conditions：t=220 ℃ ,p=l. 0 MPa, and GHSV is 20 000 mL · g-1 . h-1. With the increase of calcination temperature, the specific surface area decreases, but the catalytic activity and nickel metal active specific surface area increase first and then decrease, showing that the effect of nickel metal active specific surface area on the catalytic activity.

关 键 词：煤制天然气 NI基催化剂 均匀沉淀法 甲烷化 焙烧温度 

分 类 号：O643[理学—物理化学]