Ni_2P/Al-MCM-41催化剂的制备及其加氢脱硫性能

Preparation and hydrodesulfurization performance of Al-MCM-41-supported nickel phosphide catalysts

以硅酸钠为硅源、硫酸铝为铝源、十六烷基三甲基溴化铵(CTAB)作模板剂,采用共沸蒸馏与超声波分散技术相结合的方法制备了介孔分子筛Al-MCM-41。以Al-MCM-41为载体、硝酸镍和磷酸氢二氨为原料,采用超声波振荡、程序升温还原法制备了Ni2P/Al-MCM-41催化剂,并对Al-MCM-41和Ni2P/Al-MCM-41进行了傅里叶变换红外光谱、比表面积测定、X射线衍射、扫描电镜表征。考察了Ni2P/Al-MCM-41催化剂对噻吩加氢脱硫的催化性能。结果表明:采用超声波制得的Al-MCM-41其比表面积、孔容和孔径明显高于常规搅拌制得的Al-MCM-41,共沸蒸馏制得的Al-MCM-41其比表面积、孔容和孔径高于未共沸蒸馏的Al-MCM-41;在反应时间为5 h、548 K、3.5 MPa条件下,Ni2P/Al-MCM-41催化剂对噻吩加氢脱硫的转化率接近100%。

Al-MCM-41 mesoporous molecular sieves were prepared by the azeotropic distillation and ultrasonic dispersive technology using sodium silicate as silica source,aluminum sulfate as aluminum source and cetyltrimethyl ammonium bromide as structure-directing agent.By using Al-MCM-41 as support,nickel nitrate and diammonium hydrogen phosphate as raw materials,a series of supported Ni2P catalysts on Al-MCM-41 was prepared via the method of temperature-programmed reduction under ultrasonic oscillation.The catalysts were characterized by FTIR,BET,XRD and SEM.Hydrodesulfurization of thiophene catalyzed by Ni2P/Al-MCM-41 was carried out in a high pressure autoclave reactor.The experimental results showed that Al-MCM-41 prepared by ultrasonic dispersive technology had a much higher specific surface area,larger pore volume and pore diameter than that prepared by conventional mechanical mixing.The Al-MCM-41 prepared by azeotropic distillation with ultrasonic dispersive technology was also better than that using only ultrasonic dispersive technology.The Ni2P/Al-MCM-41 catalysts,hydrodesulfurization conversion of thiophene nearly reached 100% at the reaction time 5 h,reaction temperature 548 K,and reaction pressure 3.5 MPa.