ZrO_2 NANOPARTICLES INSIDE MESOPOROUS SBA-15 AS SUPPORT FOR HYDROTREATING CATALYSTS

摘要

Increasing awareness of the impact on environmental pollution by automobiles has shifted the responsibility of pollution control to the refineries side.As a consequence of this,the gasoline and diesel sulfur specifications are made increasingly stringent.In the case of diesel fuel,the sulfur level is expected to be lowered,all over the world to 10 - 50 ppm range.In addition fuel cells are emerging as viable energy alternatives and these applications demand feeds with sulfur levels in the range 0.1 - 1 ppm.To achieve such low sulfur levels in fuels the activity of the present catalysts need to be increased by about 7 times [1].In order to reach such low level of sulfur many approaches are followed among which variation of support is an important one [2].Wide variety of supports are employed towards achieving the above said objective with considerable success.Many supports like oxides [3,4],mixed oxides [5],zeolites [6],mesoporous materials [7,8] have been employed.Mesoporous material supported catalysts have shown excellent activities for hydrotreating functionalities [9].It is also well documented that ZrO_2,TiO_2 have showed high intrinsic activity for HDS reaction.To improve their thermal stability and surface area,mixed oxides were employed.In another approach we have prepared ZrO_2 nano particles inside the ordered mesoporous SBA-15 and employed that material as a support for Mo,CoMo,NiMo catalysts.The preparation of ZrO_2 nano particles and catalysts characterization and hydrodesulfurization catalysis forms the content of this presentation.