纳/微复合结构TiO2负载催化剂的加氢脱硫性能

以传统固相烧结法制备的不稳定的层状K₂Ti₂O₅为前驱体, 直接将钛酸钾晶须进行离子交换得到具有纳微复合结构的TiO₂载体, 等体积浸渍法制备出MoO₃/TiO₂催化剂, 运用SEM、XRD、BET、TEM等技术手段对载体和催化剂进行表征, 并考察了该TiO₂复合结构负载催化剂的加氢脱硫催化活性。SEM和XRD分析显示:该纳微米复合结构是由纳米颗粒与微米晶须构成的特殊结构, 拥有不同形貌和尺寸的TiO₂却具有相同的锐钛矿相。与单独TiO₂纳米粒子和TiO₂晶须相比, TiO₂复合结构负载催化剂表现出更佳的脱硫催化能力, 在温度310℃、压力2.1 MPa、体积空速6 h^-1、氢/油体积比600条件下, 催化剂表现出优异的DBT脱硫性能。

Hydrodesulfurization performance of nano/micro-composite TiO2 supported catalysts

With unstable layered K₂Ti₂O₅ as the precursor in the traditional preparation of solid phase sintering, nano/micro-composite TiO₂ (TiO₂-m) derived from K₂Ti₂O₅ was synthesized via ion-exchange. Supported MoO₃/TiO₂-m catalysts were prepared by incipient impregnation. Simultaneously, the properties of supports and catalysts were characterized by means of SEM, XRD, BET and TEM. An investigation into the HDS performance of MoO₃/TiO₂-m catalysts for dibenzothiophene was performed. SEM and XRD results showed that the prepared TiO₂-m supports were shaped in nano-scale particle and micron-sized whisker morphology, having the same anatase phase with different morphologies and sizes of TiO₂. Compared with pure morphology control sample, HDS tests indicated that Mo catalysts supported on TiO₂-m showed the best HDS catalytic activity under relatively mild reaction conditions (310℃, 2.1 MPa, LHSV 6 h^-1 and H₂/feed ratio 600 m³·m^-3).