Interaction between Mo and Co on Co-Mo/Al₂O₃ sulfided at high pressure (≤5.1 MPa) by means of high pressure DRIFT and EXAFS method

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• 作者：Koizumi ; Naoto ; Yamazaki ; Masato ; Hatanaka ; Shigeto ; Yamada ; Muneyoshi
• 关键词：Co-Mo/Al₂O₃ catalyst ; Ni-Mo/Al₂O₃ catalyst ; High pressure sulfiding ; Coordinatively unsaturated sites ; DRIFT of adsorbed NO ; Mo K-edge EXAFS
• 刊名：Catalysis Today
• 出版年：1997
• 出版时间：December 3, 1997
• 年：1997
• 卷：39
• 期：1-2
• 页码：33-44
• 全文大小：794 K

文摘

Co-Mo/Al₂O₃ was sulfided at high pressure (≤5.1 MPa) and was supplied for in-situ DRIFT measurement using NO as a surface probe molecule. The IR band of NO adsorbed on Co site was much stronger than that of Mo site, and the IR intensity ratio of Co site band to Mo site band was much higher when Co-Mo/Al₂O₃ was sulfided at the pressure above 1.1 MPa than when it was sulfided at atmospheric pressure. Mo/Al₂O₃, Co/Al₂O₃ and the physical mixture of them were also supplied for the high pressure DRIFT measurement. In the DRIFT spectra of the physical mixture, the intensity of the Mo site band was comparable to that of the Co site band. In the spectra of Ni-Mo/Al₂O₃, only the Ni site band was observed. Mo K-edge EXAFS showed that the dispersion of Mo of Co-Mo/Al₂O₃ is almost the same as that of the physical mixture and does not depend on the sulfiding pressure. Combining the results of the DRIFT spectra with that of Mo K-edge EXAFS, it was suggested that Co-Mo interaction induces selective formation of CUS on Co site on Co-Mo/Al₂O₃ and the interaction is promoted by higher pressure sulfiding.