NiO—WO3／F—Al2O3—SiO2催化剂活性组分的存在状态研究

应用TPR、XRD等方法研究了共胶法制备的NiO/F-Al_2O_3-SiO_2、WO_3/F-Al_2O_3-SiO_2及NiO-WO_3/F-Al_2O_3-SiO_2三种催化剂的还原性能及其活性组分的存在状态.结果表明,在NiO/F-Al_2O_3-SiO_2中NiO呈分散状态;在WO_3/F-Al_2O_3-SiO_2中WO_3与载体相互作用形成两类表面相互作用复合物;在NiO-WO_3/F-Al_2O_3-SiO_2中NiO有选择地与WO_3相互作用,形成易于还原的Ni-WO_4物种,从而改善了催化剂的还原性能.活性试验结果表明,该催化剂对萘的加氢裂化具有较好的催化活性.还应用多元线性回归法对TPR图谱进行了定量解析,求取了TPR动力学参数.

STUDIES ON STATES OF ACTIVE AGENTS OF NiO-WO_3/F-Al_2O_3-SiO_2 CATALYST

Methods of TPR and XRD were used to study systematically the existing states ofNiO, WO3 and NiO-WO3 on F-Al2O3 SiO2 support and the reduction lehavior of these threecatalysts. Results showed that NiO existed in a dispersing state on NiO/F-Al2O3-SiO2 cata-lyst. On the surface of WO3/F-Al2O3-SiO2 catalyst,there were metal-support interaction com-ponents formed from the reaction of WO3 with the surface of the support. When NiO is intro-duced into the WO3/F-Al2O3-SiO2 system, it interacts selectively with WO3-support formingNiWO4 which can be reduced easily. Finally, the kinetic parameters, such as activation ener-gy, the order of the reaction and the exponential factor of the rate equation of reduction wereobtained by mathematical analysis from the TPR curves.