Dispersed Ni-Mo sulfide catalysts from water-soluble precursors for HDS of BT and DBT via in situ produced H2 under Water gas shift conditions

Abstract

The Ni-Mo catalysts formed in invert sulfur-containing emulsions through the high-temperature decomposition of water-soluble metal precursors were tested in HDS of benzo- and dibenzothiophenes via in situ hydrogen under WGSR conditions. The formation of highly dispersed sulfide species, fully covered by Ni atoms, as well as separate Ni and Mo sulfides was proved by FT-IR, XRD, TEM, EDX mapping, and XPS techniques. The catalytic evaluation revealed the high HDS activity at 380−420 °C, p(CO) = 5 MPa, the water content of 20 wt.%, and CO:H2O molar ratio of 1.8. The catalytic behavior was estimated depending on the reaction conditions, structural features, and active phase composition. As revealed from products distribution, the lower temperature and reaction time favor the HYD reaction pathway, while the surfactant leads to the dibenzothiophene transformation through the DDS reaction route at higher temperatures. The catalysts were found to be reused at least 6 cycles in the sulfur-assisted HDS of dibenzothiophene.