%0 Journal Article
%T <br>
%A 位春蕾
%A 樊卫斌
%A 王凯
%A 王建国
%A 秦张峰
%A 董梅
%A 高洁
%J 物理化学学报
%D 2017
%R 10.3866/PKU.WHXB201704133
%X 采用浸渍法制备了Zn/HZSM-5分子筛催化剂，进行了不同温度的氢气预处理，通过X射线衍射（XRD）、氮气吸附-脱附、傅里叶变换红外（FT-IR）光谱、NH3程序升温脱附（NH3-TPD）、X射线光电子能谱（XPS）等表征技术，系统考察氢气预处理对Zn/HZSM-5分子筛结构、孔道、酸性、Zn存在状态以及在乙烯芳构化反应中的催化性能等的影响。研究结果表明，氢气预处理温度显著影响Zn/HZSM-5中Zn物种的含量和存在状态：600℃以下的氢处理，几乎不影响分子筛上Zn物种的总含量，而600℃以上氢处理时会造成Zn物种的大量流失；XPS研究显示，氢预处理的温度不同，分子筛上ZnOH+与ZnO的相对比例变化显著。结合乙烯芳构化反应性能，可以发现ZnOH+物种的含量与芳烃选择性存在较好的线性关系，说明其是促进烯烃脱氢、芳构化的主要活性中心，Zn存在状态的变化使得氢气预处理温度显著影响乙烯芳构化反应产物的分布。<br>After hydrogen pre-treatment at different temperatures, the textural and physicochemical properties of Zn/HZSM-5 were studied by X-ray diffraction (XRD), N2 adsorption-desorption, Fourier transform infrared (FT-IR) spectroscopy, temperature programmed desorption of NH3 (NH3-TPD), and X-ray photoelectron spectroscopy (XPS) techniques. The results showed that the temperatures for hydrogen pretreatment of Zn/HZSM-5 exerted a significant influence on both the contents and state of zinc species. The pre-treatment with hydrogen at temperature higher than 600℃ resulted in a significant leaching of zinc species from the catalysts, which occurred due to the reduction and sublimation of zinc species. The XPS characterization revealed that the hydrogen pre-treatment at different temperatures causes the redistribution of ZnOH+ and ZnO species in the zeolite. A linear correlation between the amount of ZnOH+ species and the selectivity to aromatics over the Zn/HZSM-5 catalysts pretreated with hydrogen at different temperatures was observed, suggesting that ZnOH+ species may promote the formation of aromatics in ethylene aromatization reaction
%U http://www.whxb.pku.edu.cn/CN/Y2017/V33/I7/1483