Beneficial effect of V on stability of dispersed MoS2 catalysts in slurry phase hydrocracking of vacuum residue: XAFS studies

Abstract

The structure and the catalytic activity of the dispersed VxMo(1−x)S2catalysts were investigated for hydrocracking (HCK) of vacuum residue (VR) with the same amount of catalyst loading of 0.113 mmol as a metal basis at 693 K and 9.5 MPa H2. The catalysts were prepared in situ in the reaction using vanadium acetylacetonate and molybdenum hexacarbonyl as V and Mo precursors, respectively. Structural properties of the dispersed catalysts were characterized by extended X-ray absorption fine structure (EXAFS) spectroscopy and transmission electron microscopy, which confirmed the formation of a well-dispersed V-MoS2phase in size range 6–8 nm. Furthermore, it was demonstrated that the V-MoS2catalysts feature higher stability in the catalyst recycle test for the VR HCK in terms of H2 consumption rate (TOF) and asphaltene conversion in comparison to monometallic sulfides of V2S3 or MoS2.