Preparation and evaluation of nicomo hydrodesulfurization catalysts supported over a binary zeolite(beta)-kit-6 siliceous material

In this work, a mesoporous nanocomposite Zeolite(Beta)-KIT-6 material was synthesized and used as a support to prepare NiCoMo catalysts. We prepared CoMo, NiMo (Co or Ni =2.4 wt.% and Mo=9.0 wt%) and (x)NiCoMo (x = 0.6, 1.2, and 2.4 wt% Ni). The support and catalysts were characterized and tested in the hydrodesulfurization (HDS) reaction of dibenzothiophene (DBT). The catalytic activity results show that the CoMo and NiMo samples are more active than the trimetallic catalysts due to a better dispersion of MoS2 (lower stacking and length) which induce a higher concentration of CoMoS and NiMoS sites. The HRTEM results also showed that the increase of the Ni concentration causes the increase of length and stacking of the MoS2 slabs. The XPS analysis exhibited that the amount of Co sulfided species in trimetallic catalysts follows a linear trend with the catalytic activity. The β-KIT-6 bimetallic supported catalysts showed better catalytic activities than those supported on KIT-6 and SBA-15 mesoporous silicas.

Keywords: KIT-6, NiMo, CoMo, hydrodesulfurization, zeolite.