Synthesis and characterization of WO₃ and WS₂ hexagonal phase nanostructures and catalytic test in sulfur remotion

The aim of the present study was the synthesis and characterization of WO₃ and WS₂ nanostructures in hexagonal phases and the evaluation of the latter as catalyst in the dibenzothiophene hydrodesulfurization reaction. 2H-WS₂ nanostructures were obtained from a precursor WO₃ nanostructure by a two-step hydrothermal/gas phase reaction under well-controlled conditions. All nanostructures were characterized by X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy, and the specific surface area of the materials was measured using the BET method. The catalytic activity and selectivity measurements of the resulting unsupported WS₂ nanocatalysts are also presented. Catalytic activity was found to be highest for the 2H-WS₂ from the WO₃ nanostructure sulfided at 773 K (rate constant of 3 × 10⁻⁷ mol/g s).