氧化镁载体和氧化钡助剂对钌基氨合成催化剂结构和性能的影响.pdf

第27卷第8期
无机化学学报
Vol 27 No8
2011年8月
CHINESE JOURNAL OF INORGANIC CHEMISTRY
1541-1549
氧化镁载体和氧化钡助剂对钌基氨合成催化剂结构和性能的影响
杨晓龙2夏春谷1唐立平12熊绪茂1慕新元1胡斌*1
中国科学院兰州化学物理研究所,兰州730000
(中国科学院研究生院,北京100049)
摘要:米用不同来源氧化镁(市售MgO-1,合成Mg0-2)作为钌基氨合成催化剂载体,浸渍法制备了添加不同Ba0助剂含量的
Ba-RuMg0催化剂,通过X射线行射(XRD)、热重一量热扫描分析(TC/DSC)、Nx低温物理吸附、透射电镜(TEM)、H2程序升温还原
(H1-TPR和CO2程序升温脱附(CO2-TPD)等手段对其进行了表征,考察了不同来源的Mg0和BaO助剂含量对负载型钌基氨合成
催化剂的物相结构、织构性质、微观形貌、Ru物种的还原性质和体系酸碱性质以及惺化剂的氨合成活性等方面的影响。结果表
明,MgO的理化性质对所制备的钉基氨合成催化剂的结构以及氨合成活性有较大影响。MgO-2比表面较大,总碱性位数量较
多,负载在其表面的Rau粒子粒径在2nm左右, NF'TLRM为1.0时,BaRu(l)MgO-2催化剂表面的Ru物种易于还原,表面存在的
弱碱性位极大地促进了氨合成活性,在400°C时活性达到15.40 Lg"iu.h(3.0MPea,5000h-),在相同反应条件下比Ba-Ru
MgO-1催化剂活性更高。
关键词:氨合成;钌:氧化镁:碱性
中图分类号:0643.3;TQ113.2;0613.61;0614.82
文献标识码
文章编号:1001-4861(2011)08-1541-09
Effect of Mgo Support and Bao Promoter on Structure and Catalytic Activity
of Ruthenium Catalysts for Ammonia Synthesis
YANG Xiao-long 2 XIA Chun-gu TANG Li-ping2 XIONG Xu-mao MU Xin-yuan HU Bin*.
Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, China)
(Graduate University of Chinese Academy of Sciences, Beiing 100049, China)
Abstract: A series of Ba-ru/Mgo catalysts were prepared by the impregnation method using commerical (mark as
Mgo-1)and synthesized Mgo(mark as Mg0-2)as the support, respectively. The catalysts were characterized b
XRD, TG/DSC, N adsorption-desorption, TEM, H TPR and CO TPD. The effect of Mgo support and Bao
promoter were investigated on the phase structure, texture structure and morphology, reduction process of
ruthenium particles, surface properties and catalytic activity in ammonia synthesis. The results indicate that the
physical and chemical properties of Mgo support have a strong impact on the structure and activity of ruthenium
catalyst. The specific surface area and total basic sites number of Mg0-2 was higher than that of Mo-1, Ru
particles supported over the surface of Mgo-2 was about 2 nm and easy to be reduced. When the molar ratio of
NR R was 1.0, weak basic sites appeared over the surface of BA-RU( 1: 1/mg0-2, which greatly promoted ti
ammonia synthesis rate. The ammonia synthesis activity was 15.40 L g a. at 3.0 Mpa, h- and 400
for Ba-ru(1: 1) /mg0-2, which was higher than that of Ba-ru/M 0-1 catalysts at the same conditions
Key words: ammonia synthesis; ruthenium; Mg0; basicity
收稿日期:2011-03-31。收修改稿日期:2011-05-15。
国家杰出青年科学基金(No.20625308)资助项目。
*通讯联系人。E-mgil:hcom?lzb,ac.cn;Tel:+86-931-4968258