MoS2 morphology and promoter segregation in commercial Type 2 Ni–Mo/Al2O3 and Co–Mo/Al2O3 hydroprocessing catalysts

A series of commercial liquid-phase-sulfided Type 2 Ni–Mo/Al2O3 and Co–Mo/Al2O3 catalysts used in different trickle-phase reactions has been characterized by (scanning) transmission electron microscopy combined with energy-dispersive X-ray analysis ((S)TEM-EDX) and X-ray diffraction (XRD) analysis. In contrast to what is reported for H2S/H2 sulfided Type 2 model catalysts, MoS2 stacking is not prominent in liquid-phase sulfided Type 2 commercial catalysts. The presence or absence of MoS2 stacking has been shown to be highly dependent on the sulfidation procedure applied. Although Type 2 commercial Ni–Mo catalysts have high MoS2 dispersion, there is a significant Ni sulfide segregation. This is not the case for their Co-containing counterparts.