Evaluation of calcined hydrocalumite-type materials as supports of CoMo and NiMo for thiophene hydrodesulfuration reaction

A hydrocalumite-type material (HC) was synthesized by the co-precipitation method, mixing Ca and Al nitrate solutions in a NaOH solution (pH ≅ 11). This solid was characterized by using different physico-chemical techniques such as: Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), temperature programmed reduction (TPR) and BET surface area measurements. Then, a portion of as-synthesized solid was calcined at 420 °C (HC 420). Both calcined and pristine solids were impregnated with Mo (15% w/w as MoO₃). Ni or Co was also impregnated on Mo/HC or Mo/HC 420 in 1(Co or Ni):3 (Mo) atomic ratios to get catalytic precursors. These solids were also characterized by the above mentioned techniques. Catalytic precursors were tested in the thiophene hydrodesulfuration reaction at 280 °C and atmospheric pressure. Cobalt promoted catalysts were more active than those promoted with Ni. However, thiophene conversions were lower than that of a conventional CoMo/γ-Al₂O₃ catalyst.