Mechanical Activation Of Ws < Sub > 2 < / Sub > Nm And Its Friction And Catalytic Properties

In the thesis, experimental investigation and theoretical analysis were carried out on the preparation process, tribology and hydrideoxygenation properties of WS2nanosheets.2H-WS2nanoplate was obtained by a mechanical activation method, in which a ball-milled mixture of WO3and S was annealed at a high temperature for some time in an atmosphere of Ar. The product was ball-milled and then annealed at840℃for2h in an atmosphere of Ar. The final nanoplate,which was hexagonal and130-150nm in size, was characterized by XRD, SEM, TEM and the difference of the products after different process has been discussed. In this experiment, sulfurization was finished in only one step, and ball-milling played a crucial role in this reaction. Annealing time and temperature are also important for the products. Assembly-stack steps were realized by a calcinations process, and the annealing temperature played a crucial role in this reaction. In order to get homogeneous hexagonal WS2nanoplates, ball-milling before annealing was necessary, which could prevent nanoplates assembling.The tribological properties of WS2nanoplates prepared from different ways were mesureed on four-ball tribo-tester. Researches have been down to test the influence of ball-milling, annealing and different sulfurizing temperature or addition and comparisons were made between low and high load. The friction mechanism of lubrication including WS2as additives was discussed preliminary. The results show that WS2nanoplates have exhibited excellent tribological performance as an additive of base oil. The more WS2was added, the higher tribological properties the basic oil have. The higher sulfurizing temperature was given, the bigger coefficient and area of friction was. If WS2had been ball-milled or annealed, the basic oil would exhibit high coefficient and big area of friction.Taking4-methyl phenol as a model, we studied the catalytic performance of hydrodeoxygenation(HDO) on WS2and Ni-WS2.The results showed that ball-milling could greatly improve the catalytic activity of WS2, and promote the conversion of direct-deoxidation(DDO). Ni element would significantly enhance reaction of hydrogenation(HYD) and inhibit direct-deoxidation. After all, adding Ni, the catalytic activity was able to be improved. When the sulfurizing temperature of Ni-WS2had been increasesd, the catalytic activity would be reduced, but the reaction of hydrogenation would be improved.