Molybdenum sulfide nanoparticles prepared using starch as capping agent. Redispersion and activity in Athabasca Bitumen hydrotreating

Abstract

Nanoparticles of MoS3 were synthesized from (NH4)2MoS4 in acid media using water-soluble starch as a capping agent. X-Ray Diffraction patterns confirmed the formation of MoS3 while Transmission Electron Microscopy results showed the presence of nanoparticles with sizes of about 30−40 nm that were covered by the polymer. X-Ray Photoelectron spectroscopy analysis confirmed the formation of molybdenum sulfides. The MoS3 nanoparticles were thermally treated in CS2/H2 and converted to MoS2 nanoparticles which showed very low or no stacking of the slabs. The activity of the latter was assessed in the hydrodesulfurization of Vacuum Gas Oil (VGO) and upgrading of Athabasca bitumen. The solids that were prepared using starch exhibited better catalytic activity when compared to commercial MoS2 nanoparticles (Hydrotreating of Vacuum Gasoil) and a NiMo/Al2O3 supported catalyst (upgrading of bitumen), and the stacking of the layers did not increase after reaction. This opens up the possibility of using the facile method of preparation here developed for the application of nanoparticles in a slurry process for heavy crude oil upgrading.