Effect of 2,6-Bis-(1-hydroxy-1,1-diphenyl-methyl) Pyridine as Organic Additive in Sulfide NiMoP/γ-Al2O3 Catalyst for Hydrodesulfurization of Straight-Run Gas Oil

Abstract

The effect of 2,6-bis-(1-hydroxy-1,1-diphenyl-methyl) pyridine (BDPHP) in the preparation of NiMoP/γ-Al2O3 catalysts have been investigated in the hydrodesulfurization (HDS) of straight-run gas oil. The γ-Al2O3 support was modified by surface impregnation of a solution of BDPHP to afford BDPHP/Ni molar ratios (0.5 and 1.0) in the final composition. The highest activity for NiMoP materials was found when the molar ratio of BDPHP/Ni was of 0.5. X-ray diffraction (XRD) results revealed that NiMoP (0.5) showed better dispersion of MoO3 than the NiMoP (1.0). Fourier transform infrared spectroscopy (FT-IR) results indicated that the organic additive interacts with the γ-Al2O3 surface and therefore discards the presence of Mo or Ni complexes. Raman spectroscopy suggested a high Raman ratio for the NiMoP (0.5) sample. The increment of the Mo=O species is related to a major availability of Mo species in the formation of MoS2. The temperature programmed reduction (TPR) results showed that the NiMoP (0.5) displayed moderate metal–support interaction. Likewise, X-ray photoelectron spectroscopy (XPS) exhibited higher sulfurization degree for NiMoP (0.5) compared with NiMoP (1.0). The increment of the MoO3 dispersion, the moderate metal–support interaction, the increase of sulfurization degree and the increment of Mo=O species provoked by the BDPHP incorporation resulted in a higher gas oil HDS activity.

Effect of Organic Additives on the Structure and Hydrotreating Activity of a CoMoS/Multiwalled Carbon Nanotube Catalyst

“…The value of the S/(Mo + Co) atomic ratio is much higher for CoMoS−CA, suggesting that the active species in this catalyst are sulfided more easily. 13,51,52 The binding energy of the S 2s main peak in all samples is 226.7 ± 0.1 eV and belongs to the terminal S 2 2− . The obtained S 2p spectra for CoMoS−CA and CoMoS−DEG samples are quite similar (Figure 6).…”

“…Also, it should be noted that there is a considerable difference in the active species sulfidation degree, as it follows from the comparison of S/(Mo + Co) atomic ratios (Table ). The value of the S/(Mo + Co) atomic ratio is much higher for CoMoS–CA, suggesting that the active species in this catalyst are sulfided more easily. ,, …”