完全液相制备中醇溶剂及醇用量对催化剂性能的影响

Effect of Alcohols and Usage Amount on Performance of Catalyst Prepared by Complete Liquid Phase Technology

在完全液相法的基础上对前驱体制备工艺进行改进,采用经醇解反应改性的异丙醇铝作为铝源制备Cu-Zn-Al双功能催化剂。考察了不同醇类及醇用量对催化剂结构及催化CO加氢合成二甲醚反应性能的影响。通过XRD,H2-TPR,NH3-TPD-MS等方法表征了催化剂的体相结构和表面性质。结果表明,催化剂制备过程中使用乙醇为溶剂,用量为150 mL时,催化剂的体相结构最好,可还原的铜物种最多,铜的分散度最高,各组分之间的相互作用力最强,催化活性最高。另外还发现,铝醇解液的老化是影响催化剂性能的重要因素。

In this work, we develop the complete liquid-phase technology in the preparation of precursor, and the modified aluminium isopropoxide prepared by alcoholysis reaction is used as aluminium sources for the preparation of Cu-Zn-AI bifunetional catalysts. The effects of different kinds of alcohols and the diffevent amounts of alcohols on the structure of catalysts and the catalytic activity of the catalysts for dimethyl ether synthesis from syngas are investigated. The catalysts are characterized by means of XRD, H2-TPR, NH3-TPD-MS. The results show that the best structure of catalyst can be obtained by ethanol and the amount is 150 mL. The favorable structure properties include： the highest amounts of reducible Cu species, the highest dispersion degree of copper, and the strongest interaction between metals. Therefore, this catalyst shows the best catalytic performance. We also find that the aging step of alcoholysis liquid of AI compo- nents is the key factor for the performance of catalysts.