Cr/Na-ZSM-5催化剂的制备及表征

Preparation and Characterization of Cr/Na-ZSM-5 Catalyst

以Cr(NO3)3为Cr源,Na/ZSM-5为载体,采用浸渍法制备了一系列Cr基催化剂(Cr的质量分数分别为0%,2.5%,5%,7.5%,10%),分别在873 K和1 073 K下焙烧.采用FT-IR、XRD、BET和SEM等测试手段对产物的结构进行了表征.在自主微型固定反应器上,采用CO2-TPD和H2-TPR反应考察了催化剂的性能.结果表明:活性组分Cr2O3均匀的分散在Na/ZSM-5载体的表面,并且对催化剂的酸碱性和还原性有一定的影响.焙烧温度的不同对催化剂有很大影响,在873 K下焙烧的催化剂具有较好的结构和形貌,而在1073 K焙烧的催化剂出现塌陷现象.

Using Cr（ NO3）3 as chromium source and Na / ZSM-5（ Si / Al = 30） as the support,a series of x Cr /Na-ZSM-5（ x = 0%- 10%） catalysts were prepared by impregnation method. The catalysts were calcined at873 K and 1 073 K respectively. The structure of the catalysts were characterized with the analysis and testing techniques,such as FT-IR,XRD,BET,SEM,CO2-TPD and H2-TPR. The results show that the active component Cr2O3 is well dispersed on the surface of the support Na / ZSM-5,and the loading of Cr2O3 has influence on the basic-acid property and reducible property. Different calcination temperature of the catalyst has a great influence on the structure and morphology of the catalysts. A phenomenon of collapse occures in the catalysts calcined at 1 073 K,which is not observed for the catalysts calcined at 873 K.