Synthesis and Catalytic evaluation of Mo(W)S2 1T polytype for Hydrotreating

Abstract

SSCI-VIDE+ECI2D+SPL:PAFNational audienceIn the last decades a strong reduction of the sulfur content in fossil fuels was achieved. However, severe environmental regulations and new resources employed still demand more active and selective catalysts. To achieve it, an increase in intrinsic activity is requested for transition metal dichalcogenides (TMD). Thanks to sulphide edges promotion by nickel and cobalt, a modification in electronic properties of the edges leads to improved activity. However, considering the limited number of active edge sites, it would be extremely interesting to induce basal planes catalytic activity in order to drastically improve the number of active sites and their accessibility for reactants. Crystals of MoS2 can exist as different polymorphs, displaying a range of electronic and optical properties, i.e. depending on the Mo coordination within a single layer and the stacking order, it is possible to find three polytypes: 1T (Tetragonal), 2H (Hexagonal) and 3R (Rhombohedral). In the case of 2H and 3R polymorphs, each Mo has trigonal-prismatic coordination with the nearby S atoms, while for 1T-MoS2, Mo is coordinated in an octahedral manner