| Project/Area Number |
03453080
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
工業物理化学・複合材料
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| Research Institution | Tohoku University |
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Principal Investigator |
YAMADA Muneyoshi Tohoku University, Faculty of Engineering, Professor, 工学部, 教授 (40091764)
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| Co-Investigator(Kenkyū-buntansha) |
TSUTSUMI Makiko Tohoku University, Faculty of Engineering, Research Associate, 工学部, 助手 (60227444)
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| Project Period (FY) |
1991 – 1993
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| Project Status |
Completed (Fiscal Year 1993)
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| Budget Amount *help |
¥6,900,000 (Direct Cost: ¥6,900,000)
Fiscal Year 1993: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1992: ¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 1991: ¥4,100,000 (Direct Cost: ¥4,100,000)
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| Keywords | Metal Sulfide / Chelating agent / Unsaturated Coordination / Hydrotreating / Hydrodesulfurization / Probe Molecule / Zeolite / Molybdenum / 形状選択性 / クラスター / 触媒調製 / 相互促進作用 / センサー / クラスタ- |
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| Research Abstract |
We have studied the character and catalysis of cobalt/molybdenum sulfides by means of spectroscopic method. According to the results it is concluded that catalysis of metal sulfide is determined by cluster size, valence and coordination of the center atom. Individual control of each factor by various method is essential to develop the active hydrotreating catalyst. This study was performed to attain the basis for new catalyst design.
Hydrodesulfurization (HDS) of benzothiophene was carried out over cobalt-molybdenum (Co-Mo) catalyst after sulfurization. The synergic effect was extended in hydrogen sulfide (H_2S) atmosphere. Co-Mo catalysts surface was observed by means of NO probe to fine that the synegy of the sulfides evolved from that of the precursor oxides. The effect of sulfiding on the catalyst HDS activity was investigated by comparing the activities of catalysts which were pretreated by sequential sulfiding and reducing. These activity tests showed that while presulfiding induc
… More
ed intrinsic activity of the catalyst, prereduction induced a deteriorating effect on the catalyst activity even after a prolonged sulfidation. Spectroscopic studies on the presulfided and/or prereduced Co-Mo catalyst were conducted and it was shown that the deteriorating of the catalyst activity induced by the prereduction was related to the size of molybdenum sulfide.
Molybdenum dicluster was successfully introduced into zeolite cage maintaining the Mo-Mo bond. The activity of Mo/zeolite catalyst is lower than conventional Mo/Al_2O_3 catalyst and the deteriorating effect of H_2S atmosphere on the catalyst activity is remarkable on Mo/zeolite. There results imply that the size of molybdenum sulfide was limited in zeolitecage.
Co-Mo/Al_2O_3 catalyst was prepared using chelating agent in an aqueous solution. The HDS activity of the chelate-added catalyst was higher than the commercially available Co-Mo/Al_2O_3 catalyst and the promoting effect was most remarkable when cobalt and molybdenum were simultaneously supported on Al_2O_3. It was suggested that the chelating agent has a role of increasing Co surface density ; thus, increasing the active site. Less
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