Abstract: To explore the influence of the initial stage activity stabilization on diesel HDS performance of NiMo/Al2O3 catalyst, a series of sulfided NiMo/Al2O3 samples was prepared by wet sulfidation and dry sulfidation method respectively. The straight-run diesel was used to treat the sulfided samples to stabilize the initial HDS activity of the catalysts for 48 hours. The HDS activities and coke depositions of the sulfided NiMo/Al2O3 catalysts with or without initial stabilization procedure were tested. The samples before and after reaction were characterized by means of XPS、TEM、TG-MASS and CAT-CS techniques. The results showed that initial stabilization procedure improves the stability of both fresh sulfided catalysts by wet and dry method and gives little changes for the active phase structure of sulfided NiMo/Al2O3 catalyst, but increases coke deposition on the active phase, which is benefit to the activity stability due to the modification of active phase structure by deposited coke.

Key words: dry sulfidation, wet sulfidation, initial stage activity stablization, coke deposition, hydrodesulfurization, stability