TiO2改性AlPO4-5/Al2O3负载W-Ni催化剂中Ni-W的化学状态

以偏钛酸形式将TiO2引入到AlPO4-5/Al2O3复合载体中，以W-Ni为活性金属制备不同TiO2含量的复合载体催化剂。采用紫外漫反射光谱（DRS）、激光拉曼光谱（LRS）、程序升温还原（TPR）等对钛改性AlPO4-5/Al2O3复合载体和催化剂进行表征。结果表明，TiO2引入复合载体，促进了Ni与W结合，有效抑制镍离子扩散到氧化铝晶格中，减少了惰性镍铝尖晶石的形成，有利于发挥镍的助催化作用；TiO2的引入使得钨物种趋向于以多核聚钨酸WO3形式存在；镍、钨物种在TiO2改性的复合载体上更容易被还原，有利于催化剂的硫化。

CHEMICAL STATES OF Ni-W IN NiW/AlPO4-5-Al2O3 CATALYST MODIFIED BY TiO2

Titania modified AlPO4-5/Al2O3 composite support was prepared by adding metatitanic acid to AlPO4-5/Al2O3 and a series of catalysts with various TiO2 content were prepared using W-Ni metals as active components. UV diffusion reflectance spectroscopy (DRS) in conjunction with laser Raman spectroscopy (LRS) and temperature programmed reduction (TPR) technique were used to characterize TiO2 modified AlPO4-5/Al2O3 supports and catalysts. Test results show that the addition of TiO2 promotes the combination of Ni and W, which can effectively inhibit the migration of nickel cations into alumina lattice to reduce the formation of inert nickel-aluminum spinel, thus the co-catalytic performance of nickel is enhanced. The presence of TiO2 makes tungsten species tend to form multicore tungsten acid WO3. The tungsten and nickel species on TiO2 modified composite support are more likely to be reduced and be sulfurized.