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

The γ-Al 2 O 3 -supported Anderson-type complexes (NH 4 ) 4 [NiMo 6 − x W x O 24 H 6 ]·5H 2 O (x = 0, 3 or 6) were carburized with CH 4 /H 2 (1:4) mixture (denoted by NiMo 6 − x W x -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 NiMo 6 -C/Al were greater than those of NiW 6 -C/Al and NiMo 3 W 3 -C/Al. XRD results evidenced a bulk structure typical of Mo 2 C, W 2 C, WC and NiC. FT-IR verified the absence of bands corresponding to metal oxides. Generally, the catalytic activity toward a given reaction product of NiMo 6 -C/Al was greater than those of NiW 6 -C/Al and NiMo 3 W 3 -C/Al due either to its better textural properties or to a more complete transformation of the metal phases into active ones. [ABSTRACT FROM AUTHOR]