Pavel Afanasiev

Overview of support effects in hydrotreating catalysts

The commercial hydrotreating catalysts are usually composed of a sulfide active phase supported on alumina. It has been known for more than 15 years that other supports might lead to enhanced catalytic properties. The present article summarizes the progress which have been made in this area, often related to new methods of preparation of supports, active phases deposition or activation procedures. The properties of active phases supported on oxides, pure or mixed, basic and acidic supports, zeolites, mesoporous materials, carbon and clays are examined.

Preparation, structural and hydrotreating catalytic properties of unsupported NiRh2S4

NiRh2S4 unsupported catalysts were prepared by a coprecipitation method and characterized by X-ray diffraction (XRD), chemical analysis, specific surface area measurements and high-resolution transmission electron microscopy (HRTEM). It has been shown by XRD and HRTEM that the main phase of the prepared solids has a cubic spinel type structure. The catalytic properties were evaluated in the hydrodesulfurization (HDS) of thiophene and the hydrogenation (HYD) of tetralin. The intrinsic HDS and HYD activities of the NiRh2S4 catalyst were compared with dispersed Rh, Mo binary sulfides and ternary NiMoS and NiCr2S4 sulfides. The intrinsic HDS activity of NiRh2S4 is higher than the sum of those of the individual Ni3S2 and Rh2S3 compounds, suggesting the existence of a synergistic effect between Ni and Rh.