SiO_2-TiO_2-ZrO_2复合氧化物的制备及其在加氢脱硫中的应用

Preparation of Composite Oxide SiO_2-TiO_2-ZrO_2 and Application in Hydrodesulfurization

采用溶胶-凝胶法制备了SiO2-TiO2-ZrO2复合氧化物.考察了Si/Ti/Zr摩尔比对样品比表面积、孔结构、酸性和晶体结构的影响,同时考察了样品的热稳定性;采用X射线衍射、N2物理吸附、吡啶吸附红外光谱等技术对样品进行了表征;以二苯并噻吩(DBT)和柴油样品的加氢脱硫为探针反应考察了该复合氧化物作为加氢脱硫催化剂载体的可行性.结果表明,SiO2-TiO2-ZrO2复合氧化物为介孔材料,其比表面积和热稳定性明显高于单一及二元复合氧化物;当nSi/nTi/nZr=0.163/0.809/0.028时,样品比表面积为315.32 m2/g、孔容为0.33 cm3/g、孔径为12.0 nm;以此为载体载负MoP催化剂的DBT加氢脱硫率可达99.6%,柴油样品脱硫率达96%;催化剂长周期运行1200h后,脱硫活性稳定.

The SiO2-TiO2-ZrO2 composite oxide was prepared by Sol-Gel method.The effects of n（Si）/n（Ti）/n（Zr） on the specific surface area,pore structure,acidity and crystal structure of the composite oxide were examined,and the thermal stability of samples was also characterized.The samples were tested by XRD,nitrogen absorption and infrared spectroscopy of absorbed pyridine.The feasibility of the composite oxide as the support of hydrofining catalyst was investigated by using dibenzothiophene as a model compound through hydrodesulfurization（HDS） reactions.The results indicated that mesoporous particles of the composite oxide were obtained.Compared with single and binary composite oxide,the specific surface area,the thermal stability and crystal stability of SiO2-TiO2-ZrO2 composite oxide were obviously improved.When n（Si）/n（Ti）/n（Zr） is equal to 0.163/0.809/0.028,the specific surface is 315.32 m2/g,pore volume is 0.33 cm3/g and the aperture is 12.0 nm.The dibenzothiophene sulfur removal rate for MoP/SiO2-TiO2-ZrO2 is 99.6% and desulfurization of diesel samples is above 96%.And desulfurization activity of catalyst is stability after 1200 h running.