Catalytic activity of needle-like Ni/WS2 particles Original Research Article

The catalytic activity of WS2 for the HDS of thiophene can be enhanced by annealing with the powders of Ni and Co at about 800°C under vacuum. In the case of Ni, the same treatment resulted in the formation of unique shapes of the particles such as tubes and/or fibers, whereas for Co, the flake-like particles were formed. Thermodynamics suggest that WS2 is more willing to share sulphur with Ni than with Co. It was postulated that the interactions of Ni with not fully coordinated sulphur ions at the edges of the topmost layer of the WS2 crystals was the origin of tube formation which was most pronounced at Ni:[Ni+W] ratio of about 0.25.