摘要
以X射线粉末衍射(XRD)27Al固体核磁共振(MASNMR)、低温氮吸附、NH3-TPD、吡啶吸附原位红外光谱(insituIR)等手段表征酸处理、水蒸气处理及其混合处理改性的无黏结剂H—ZSM-5沸石催化剂,考察不同改性方法对其组成、晶体结构、孔结构以及表面酸性质的影响,揭示了水蒸气处理对催化剂物性的强烈调变作用。对比改性前后上述催化剂用于50%稀乙醇脱水制乙烯催化反应中所得转化率和乙烯选择性,发现水蒸气-HCl处理相结合改性的催化剂活性最佳。
Binder-free H-ZSM-5 zeolite catalyst was modified by the treatment with HCl, steaming and steaming combined with HCl treatment, respectively. Several important properties, such as the composition, crystal and pore structure, and surface acidity etc. , of the modified catalysts were investigated in detail with X-ray diffraction (XRD), 27Al MAS NMR, N2 adsorption, NH3-TPD and pyridine-adsorbed in situ infrared spectroscopy. The strong effect of steaming on the properties of catalyst has been revealed. The conversion and selectivity of ethylene in 50% hydrous ethanol dehydration to ethylene over the raw and modified zeolite catalysts were compared. It is found that the catalyst modified by steaming combined with HCl treatment possesses the best reaction activity.
出处
《石油学报(石油加工)》
EI
CAS
CSCD
北大核心
2008年第B10期282-290,共9页
Acta Petrolei Sinica(Petroleum Processing Section)
基金
国家自然科学基金项目(No.2003CB615801)资助