【作者】 马娜；

【导师】 季生福；

【作者基本信息】 北京化工大学 ， 化学工程， 2007， 硕士

【摘要】 由于过渡金属碳化物具有贵金属的性质，已在脱硫、脱氮、异构化等反应中表现出优异的催化性能，但以传统的Al₂O₃、SiO₂为载体在反应过程中活性组分易团聚，催化剂的稳定性较差。介孔分子筛SBA-16具有高的比表面和水热稳定性，如将碳化物负载于SBA-16上可避免上述问题，基于这样的目的，本文制备了不同碳化物含量的SBA-16介孔分子筛催化剂，并对其结构特征和加氢脱硫催化性能进行了研究。以F127和P123为模板剂，TEOS为硅源，酸性条件下水热合成SBA-16介孔分子筛。并以SBA-16为载体，浸渍法制备了MoO₃／SBA-16（Si／Mo=30～1.0），对其进行程序升温碳化得到相应的Mo₂C／SBA-16催化剂。结果表明：所有样品均保持SBA-16典型的立方笼状介孔结构，具有良好的低温深度加氢脱硫活性。又分别用浸渍法和水热晶化法制备了WO_3SBA-16（Si／W=40～7.5），经过程序升温碳化得到相应的W_xC／SBA-16催化剂。结果表明：所有样品均保持SBA-16典型的立方笼状介孔结构，水热晶化法制得的样品更易保持SBA-16的结构特性和具有更好的加氢脱硫性能。水热晶化法制得的W_xC／SBA-16样品，当Si／W=30～10时，碳化钨的物相为W₂C；当Si／W=7.5时，碳化钨为W₂C和WC的混合物相。最后，水热合成WO_3SBA-16（Si／W=40～7.5）的基础上浸渍Mo制备含W、Mo氧化物的SBA-16（Si／Mo=30～7.5），经程序升温碳化得含W、Mo碳化物的SBA-16催化剂。结果表明：所有样品均保持SBA-16典型的介孔结构，且Mo组分的引入显著提高了催化剂的加氢脱硫性能。更多还原

【Abstract】 Transition metal carbides have showed superior activities in hydrodesulfurization, dehydronitrogen and isomerization as their catalytic properties similar to those of the noble metals. Using Al₂O₃ and SiO₂ as Cartier of carbides catalysts can’t meet the requirements because of having inferior dispersion of active components and worse stability. The mesoporous molecular sieve SBA-16 was reported to have many advantages as follows: Very high surface area, high thermal stability. It may avoid active components to get together and improve the stability of catalysts as carrier supported transition metal carbides. So in this paper, the preparation, characterization and catalytic performance of catalysts on SBA-16 cartier were mainly investigated.Firstly, SBA-16 was prepared by hydrothermal synthesis method using TEOS as silicate material and F127 and P123 as surfactant in the acidic condition. A series of MoO3/SBA-16 catalysts with different Mo contents （Si/Mo molar ratio is 30～1.0） were prepared by the incipient wetness method. Then the corresponding Mo₂C/SBA-16 catalysts were obtained by a temperature programmed carburization method. The results indicated that have the best relative catalytic activity in deep HDS of thiophene.Secondly, A series of WO_3SBA-16 catalysts with different W contents （Si/W molar ratio is 40～7.5） were synthesized by the incipient wetness method and for the first time by hydrothermal synthesis method in acidic medium. Then the corresponding W_xC/SBA-16 catalysts were prepared by a temperature programmed carburization method. The results indicated that both oxides and metal carbides were still maintained well cage-like structure of SBA-16 mesoporous molecule sieve with a cubic symmetry. In the tungsten carbide catalysts prepared by hydrothermal synthesis method, the tungsten carbide was the W₂C phase when Si/W was from 30 to 10. However, the tungsten carbides were the mixture phases of W₂C and WC when Si/W was 7.5. The WxC/SBA- 16 catalysts prepared by hydrothermal synthesis method had maintained better ordered mesoporous structure and exhibited better catalytic activity for HDS of thiophene than these by the incipient wetness method.Finally, Mo components were incorporated into WO_3SBA-16 samples in impregnation step. Then the corresponding W and Mo carbides-SBA-16 catalysts were prepared by a temperature programmed carburization method. The results indicated that all samples were still maintained well cage-like structure of SBA-16 mesoporous molecule sieve with a cubic symmetry. The catalytic activity for the thiophene improved in evidence after Mo loading has the higher conversion of thiophene than the corresponding W_xC/SBA-16 catalysts.更多还原