Influence of Frame Connectivity of SBA-15 and KIT-6 Supported NiMo Catalysts for Hydrotreating of Gas Oil

Abstract

The feasibility of mesoporous silica as support to NiMo catalysts for hydrotreating of gas oil derived from Athabasca bitumen was tested in a trickle bed reactor at industrial conditions. High quality two dimensional (2D) hexagonal SBA-15 and three dimensional (3D) cubic KIT-6 supports were prepared by sol–gel method. The supports and catalysts were characterized by different characterization techniques such as N2 physisorption, X-ray diffraction (XRD), Temperature programmed reduction (TPR), and DRIFT spectroscopy. The XRD and N2 adsorption–desorption analysis shows the stability of structure after metal loadings. Presence of high NiMoS centres which is responsible for higher hydrotreating activities in KIT-6 supported catalysts is demonstrated by DRIFT spectroscopic analysis. HDN and HDS activities of NiMo catalysts supported on SBA-15 and KIT-6 were studied using coker light gas oil at temperature, pressure and LHSV of 370 °C, 8.8 MPa and 2.0 h−1, respectively. KIT-6 supported catalysts shows much higher hydrodesulfurization (HDS) and Hydrodenitrogenation(HDN) activities compared to SBA-15 counterpart due to the fact that 3D-interconnected mesopores caused better dispersion of active species and faster diffusion of reactants and products. The higher amount of MoS2 phases, better dispersion and higher concentration of the catalytically active edge sites (NiMoS) formation in the KIT-6 supported NiMo catalyst have resulted in superior hydrotreating activity when compared with the SBA-15 supported NiMo catalysts. In contrast to the material with 2D hexagonal symmetry, the 3D cubic pore structure is highly branched and is accessible, making it an excellent support.