Hydrodesulfurization of Thiophene on Activated Carbon Fiber Supported NiMo Catalysts

Activated carbon microfiber (ACF)-supported NiMo-based catalysts were prepared for the hydrodesulfurization (HDS) of thiophene. The catalysts were characterized for their physicochemical properties, using the Brunauer-Emmett-Teller, scanning electron microscopy, high-resolution transmission electron microscopy, X-ray photoelectron spectroscopy, X-ray diffraction, temperature-programmed reduction, and temperature-programmed desorption analysis. The effects of the NiO (promoter)-to-MoO3 (active metal oxide) ratios were experimentally determined on the HDS of thiophene (3% v/v in hydrogen) over the temperature range of 300-370 degrees C. The catalytic activity tests showed the optimum reaction temperature and weight ratio of NiO to the binary oxide mixture to be 350 degrees C and 0.25 at 12% (w/w) loading of MoO3, respectively. The pseudo first order rate constant and activation energy for the HDS reaction were determined to be 980 X 10(-6) mole thiophenes/gram catalyst min(-1) and 46.3 kJ/mol, respectively, which were greater and smaller, respectively, than those for most of the supported metal catalysts discussed in literature for the HDS of thiophene. The prepared NiMo-based catalyst was found to be stable, with negligible loss of activity observed up to 30 h of the test run.