Deactivation study of unsupported nano MoS2 catalyst

The stability of catalyst is of great importance for a long-term operation. In this paper, the hydrodesulfurization stability and deactivation mechanism of unsupported nano MoS2 catalyst was examined with light cycle oil as feedstock under an extreme hydrotreating condition for 160 h. A typical supported catalyst was also studied for comparison purpose. The results show that the activity of nano MoS2 can be well maintained after initial deactivation in the first 60 h time-on-stream. Less coke was found on spent nano MoS2 than on the spent supported catalyst, though coke deposition is identified as the main cause of deactivation for the nano catalyst. Without acidic supports, only soft coke is formed on the surface of catalyst. Unlike the supported catalyst, decomposition of active phase played a minor role in the deactivation of nano MoS2.