Hydrothermal synthesis of bulk Ni impregnated WO3 2D layered structures as catalysts for the desulfurization of 3-methyl thiophene

Abstract

Unsupported Ni/W catalysts were synthesized using a hydrothermal method to form WO3. The WH-x and WN-x (x is the hydrothermal time) samples were impregnated with Ni and calcined at 450 ºC. The X-Ray diffraction, Raman spectroscopy, and UV–vis results showed that the monoclinic tungsten oxide phase forms the WOx phase in tetrahedral and octahedral coordination. Only in the Ni/WN-x series was detected the octahedral Ni species responsible for promoting the active phase. The XPS analysis revealed that 70% of the Ni promotes the WS2 active phase, forming the NiWS phase and 90% of W formed the WS2 phase. The catalysts tested in the 3-methylthiophene hidrodesulfurization reaction showed good activity under low pressure conditions. The largest activity of the Ni/WN-24 catalyst correlates well with the shorter WS2 slab lengths and the Ni-promoting the active phase. Interestingly, isoprene was obtained as the main product, indicating that the reaction mechanism followed the direct desulfurization (DDS) pathway.