Hydrodesulfurization of benzothiophene over zeolite-supported catalysts prepared from Mo and Mo-Ni sulfide clusters
Molybdenum sulfide cluster [Mo{sub 3}S{sub 4}(H{sub 2}O){sub 9}]{sup 4+} and nickel-molybdenum bimetallic sulfide cluster [Mo{sub 3}NiS{sub 4}Cl(H{sub 2}O){sub 9}]{sup 3+} were incorporated into zeolites NaY, HUSY, NaH{beta}, Na-mordenite (NaMOR), and KL by aqueous ion exchange. EXAFS data revealed that the structure of the molybdenum sulfide cluster remained virtually intact after ion exchange. However, the incomplete cubane-type structure of the cluster might be lost after thermal treatment at 573 K. The structure of the cluster in Mo{sub 3}S{sub 4}/NaY and Mo{sub 3}S{sub 4}/KL seems to have changed to the MoS{sub 2}-like structure through the hydrodesulfurization (HDS) reaction, although a considerably high level of dispersion was kept. Mo{sub 3}S{sub 4} cluster catalysts loaded on NaMOR and KL exhibited a higher level of activity for HDS of benzothiophene than Mo{sub 3}S{sub 4} catalysts loaded on the other zeolites. Benzene was formed through acid-catalyzed dealkylation of ethyl-benzene, the primary HDS product. Alkylation of benzothiophene with alkenes derived from the cracking of decane as the solvent also occurred. The acidity seems to be produced through the ion exchange and reduction of cationic clusters during activation. Over HUSY- and NaH{beta}-supported catalysts benzene was the major HDS product. Nickel incorporation into the Mo{sub 3}S{sub 4} zeolite catalysts remarkably enhanced the HDS activity. Introduction of the Mo{sub 3}NiS{sub 4} core into zeolite as a precursor resulted in catalysts with higher HDS activity than that of Mo{sub 3}S{sub 4} core and Ni{sup 2+} independently; it is conceivable that the intimate interaction between nickel and molybdenum in the precursor is effective at producing active species.
- Research Organization:
- Univ. of Tokyo, Yayoi (JP)
- OSTI ID:
- 20000965
- Journal Information:
- Journal of Catalysis, Journal Name: Journal of Catalysis Journal Issue: 1 Vol. 187; ISSN 0021-9517; ISSN JCTLA5
- Country of Publication:
- United States
- Language:
- English
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