Effect of the structural modification by carbiding of alumina supported Anderson-type (NH4)4[NiMo6−xWxO24H6]·5H2O on hydrodesulfurization, hydrodechlorination and selective oxidation

• Published in: Catalysis communications Vol. 99; pp. 89 - 93
• Main Authors: Puello-Polo, Esneyder, Diaz, Yraida, Brito, Joaquín L.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-08-2017
• Subjects: Anderson-type heteropolyoxomolybdotungstate; Hydrodechlorination; Hydrodesulfurization; NiMoW carbides; Selective oxidation; Stoichiometric proportions; Selective oxidation; NiMoW carbides; Anderson-type heteropolyoxomolybdotungstate; Stoichiometric proportions; Hydrodechlorination; Hydrodesulfurization
• ISSN: 1566-7367; 1873-3905
• DOI: 10.1016/j.catcom.2017.05.017

The γ-Al2O3-supported Anderson-type complexes (NH4)4[NiMo6−xWxO24H6]·5H2O (x=0, 3 or 6) were carburized with CH4/H2 (1:4) mixture (denoted by NiMo6−xWx-C/Al). These solid compounds have been tested in a continuous flow, fixed bed reactor for thiophene hydrodesulfurization and polychlorinated biphenyls hydrodechlorination, and in (semi-) batch reactor for dibenzothiophene selective oxidation. The specific surface area and pore volume of NiMo6-C/Al were greater than those of NiW6-C/Al and NiMo3W3-C/Al. XRD results evidenced a bulk structure typical of Mo2C, W2C, WC and NiC. FT-IR verified the absence of bands corresponding to metal oxides. Generally, the catalytic activity toward a given reaction product of NiMo6-C/Al was greater than those of NiW6-C/Al and NiMo3W3-C/Al due either to its better textural properties or to a more complete transformation of the metal phases into active ones.
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•Catalysts obtained at stoichiometric proportions of x=0 presented the best catalytic activity.•Catalysts presented a mix of Mo2C, W2C, WC and NiC when the stoichiometric proportons of x=3 and 6.•The sulfiding process improved the HDC and HDS catalytic activity of the catalysts.