La和Mn助剂对完全液相法制备的CuZr浆状催化剂结构和性能的影响

Effect of La and Mn Promoters on Structure and Performance of CuZr Catalyst Prepared by Complete Liquid-Phase Technology

利用完全液相法分别制备了CuZr和La,Mn促进的CuZr浆状催化剂,考察了催化剂在合成气一步合成二甲醚反应中的催化性能,并采用NH3程序升温脱附、X射线粉末衍射、N2吸附-脱附、X射线光电子能谱和程序升温还原等对其进行了表征.结果表明,在利用完全液相法制备的La-Mn-CuZr催化剂中,La和Mn的加入可促进催化剂活性组分的分散,提高了催化剂的比表面积和ZrO2的表面缺陷,增加了高分散CuO和可还原CuO数量,增强Cu和Zr之间的相互作用,进而使催化剂活性大幅度提高.

A CuZr slurry catalyst promoted by La and Mn additives was prepared by complete liquid-phase technology. The performance of the catalyst for direct synthesis of dimethyl ether from syngas was evaluated in a slurry reactor. The catalyst was characterized by NH3 temperature-programmed desorption,powder X-ray diffraction,N2 adsorption-desorption,X-ray photoelectron spectroscopy,and H2 tempera-ture-programmed reduction. The results indicated that the addition of La and Mn promoters to the CuZr slurry catalyst effectively improved the active metal dispersibility and increased the catalyst surface area. The presence of La and Mn also increased the surface vacancy of ZrO2,improved the number of highly dispersed CuO and reducible CuO,and thereby enhanced the interaction between Cu and Zr. Consequently,the catalyst activity was obviously increased.