聚乙二醇和液体石蜡介质对完全液相法制Cu-Zn-Al催化剂结构及CO加氢催化性能的影响

Effect of PEG and Liquid Paraffin as Medium on the Structure and CO Hydrogenation Performance of Cu-Zn-Al Catalyst Prepared by Complete Liquid Phase Technology

催化剂的形成和使用环境对催化剂的结构和性能会产生重要的影响.我们采用完全液相法,以PEG-400和液体石蜡分别作为热处理介质制备Cu-Zn-Al催化剂,用X射线粉末衍射、H2程序升温还原、N2吸附、X射线光电子能谱对其进行表征,考察热处理介质对催化剂结构的影响;以相应的热处理介质作为浆态床反应介质,考察介质对CO加氢催化反应性能的影响.结果表明,PEG-400作为热处理介质有助于提高催化剂的比表面积、Zn O的分散度和表面铜含量,催化剂中存在难还原的Cu+,有利于形成Cu+-Cu0之间的协同作用;在反应过程中,PEG-400作为反应介质可以抑制铜晶粒的长大,有利于乙醇的生成及C5烃选择性的提高,但催化剂的结构和表面组成会发生较大的变化.

The formation and use environment will have a major impact on the structure and properties of catalysts.The Cu-Zn-Al catalyst prepared by complete liquid-method technology with PEG-400 and liquid paraffin as heat treatment medium,and characterized by X-ray diffraction,H2temperature-programmed reduction,N2 adsorption and X-ray photoelectron spectroscopy,the effect of heat treatment medium on the catalyst structure was evaluated.The effect of reaction medium on the CO hydrogenation performance of catalyst was investigated with the corresponding heat treatment medium as slurry bed reaction medium. The results showed that PEG-400 as heat medium was helpful to improve the specific surface area of catalysts,the dispersion of Zn O and the surface copper content,the existence of anti-reducibility Cu+in the catalyst was conducive to form the synergy between Cu+and Cu0,PEG-400 as reaction medium could inhibit the grain size of copper growth in the reaction,improved the selectivity of ethanol and C5 hydrocarbon,but structure and surface composition of catalyst had great changes.