| Abstrakt: |
The bulk Ni and Co boride alloys were synthesized using the typical reduction method with potassium borohydride in different Ni/(Ni + Co) ratios, 273 K and under an N2 atmosphere. These solids were characterized before the DBT HDS reaction using different techniques such as: X-ray diffraction (XRD), surface measurements (BET specific area, pore volume and pore diameter), chemical analysis, elemental analysis, differential calorimetry of scanning (DSC), X-ray photoelectron spectroscopy (XPS), temperature programmed reduction (TPR), and transmission electron microscopy (TEM); and after the reaction by XRD and chemical analysis. These bulk borides were tested as catalysts in the HDS reaction of DBT. Ni/(Ni + Co) ratios of 0.0 and 0.25 showed the highest catalytic activity. After that, the catalytic activity decreased and remained almost constant as the Ni content increased. XPS and XRD studies revealed that these metal borides partially decompose under reaction conditions to form sulfur species. Both phases, boride and sulfur compounds, are responsible for the catalytic activity. On the other hand, unlike classical supported hydrotreating catalysts, these boride alloys are more reactive towards the hydrogenation pathway in the DBT hydrodesulfurization (HYD) reaction, showing a similar behavior to noble metal-based catalysts, but with the advantage of being much cheaper and thio resistant. It is particularly interesting when the aromatic content in the diesel fractions must be reduced. Additionally, for the first time, the kinetic constants of the DBT hydrodesulfurization reaction using these Co and Ni alloys were established. [ABSTRACT FROM AUTHOR] |
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