Abstract:

Co/S-1 catalysts with different cobalt（Co） contents were prepared by a simple impregnation method using pure silica MFI zeolite（S-1） as carrier and applied to the dehydrogenation of propane.Co/S-1 was characterized by X-ray diffraction（XRD），nitrogen adsorption desorption，and Fourier transform infrared spectroscopy（FT-IR）.The results showed that Co was loaded on the S-1 carrier and reacted with the Si—OH of S-1 to form unit point Co species and ultra small Co nanoclusters，which were the main active centers for propane dehydrogenation.The loading amount of Co had a significant impact on propane dehydrogenation.When the loading amount was low，there were fewer active Co species and propane dehydrogenation performance was poor.When the loading amount was high，the Co species would agglomerate into large particles，which was not conducive to the propane dehydrogenation reaction.By optimizing the preparation conditions，it was found that when the Co loading amount was 1%（mass fraction），the propane dehydrogenation performance of Co/S-1 was optimal.After 5 cycles of recycling，there was no significant decrease in propane conversion，propylene selectivity，and propylene yield.

Key words: Co/S-1 catalyst, propane dehydrogenation, propylene, active sites, structure-activity relationship