摘要
采用水热稳定的MgAl2O4尖晶石对-αAl2O3载体表面进行修饰,采用具有较强亲水性能的SnO2对活性组分Nb2O5进行修饰,制备了SnO2-Nb2O5/MgAl2O4/-αAl2O3催化剂,并用于环氧乙烷水合制乙二醇反应.采用X射线衍射、红外光谱和程序升温脱附研究了Sn/Nb摩尔比对催化剂酸性、环氧乙烷在催化剂表面的吸附状态和吸附强度以及催化剂性能的影响.结果表明,Sn/Nb摩尔比明显影响催化剂的组成和结构;催化剂的结构不同,环氧乙烷在催化剂表面的吸附强度存在明显差别,催化剂的催化性能明显不同.
The SnO2-Nb2O5/MgAl2O4/α-Al2O3 catalyst was prepared by modification of α-Al2O3 with MgAl2O4 along with the doping of SnO2 in Nb2O5 and used for hydration of ethylene oxide （EO） to monoethylene glycol （MEG）. The effects of Sn/Nb molar ratios on the structure, the acidity and the catalytic performance of the catalyst were investigated by using X-ray diffraction, infrared spectroscopy, temperature-programmed desorption of NH3 and of EO. The phase composition of niobium species, the catalyst acidity, and the adsorption states and strength of EO were markedly influenced by the Sn/Nb molar ratios, leading to different EO conversion and MEG selectivity. MEG selectivity of 95.2 % was achieved at n （Sn）/n （Nb） = 0.8. The characterization of the used catalyst revealed that no obvious change was recorded, indicating the good hydrothermal stability of the catalyst.
出处
《催化学报》
SCIE
CAS
CSCD
北大核心
2007年第4期345-350,共6页
基金
国家重点基础研究发展计划(973计划
2003CB615807)
上海市科委科研项目(03DJ14004)
关键词
氧化铌
氧化铝
氧化锡
镁铝尖晶石
环氧乙烷
水合
乙二醇
niobium oxide
alumina
stannic oxide
magnesia-alumina spinel
ethylene oxide
hydration
monoethylene glycol
