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To better understand the nature of carbon nanotubes supported Co-Mo catalysts (Co-Mo/CNTs) for selective hy- drodesulfurization (HDS) of fluid catalytic cracking (FCC) gasoline,studies are carried out using in situ Fourier transform infrared spectroscopy (FT-IR).The catalytic performances of Co-Mo/CNTs catalysts were evaluated with a mixture of cy- clohexane,diisobutylene,cyclohexene,1-octene (60:30:5:5,volume ratio) and thiophene (0.5%,ratio of total weight) as model compounds to simulate FCC gasoline.The HDS experimental results suggested that the HDS activity and selectivity of Co-Mo/CNTs catalysts were affected by Co/Mo ratio;the optimal Co/Mo atomic ratio is about 0.4,and the optimum reaction temperature is 260℃.The in situ FT-IR studies revealed that 1-octene can be completely saturated at 200℃.In the FT-IR spectra of diisobutylene,the characteristic absorption peak around 3081 cm~(-1) for the stretching vibration peak of=C-H bond was still clear at 320℃,indicating that diisobutylene is difficult to be hydrogenated.As for the thiophene,no characteristic absorption peak could be found around 3092 cm~(-1) and 835 cm~(-1) when the reaction temperature was raised to 280℃,indi- cating that thiophene had been completely hydrodesulfurized.On the basis of FT-IR results,it can be deduced that thiopbene HDS reaction occurred mainly through direct hydrogenolysis route,whereas thiophene HDS and diisobutylene hydrogenation reaction over Co-Mo/CNTs catalysts might occur on two different kinds of active sites.
To better understand the nature of carbon nanotubes supported Co-Mo catalysts (Co-Mo / CNTs) for selective hy drodesulfurization (HDS) of fluid catalytic cracking (FCC) gasoline, studies are carried out using in situ Fourier transform infrared spectroscopy -IR). The catalytic performances of Co-Mo / CNTs catalysts were evaluated with a mixture of cy- clohexane, diisobutylene, cyclohexene, 1-octene (60: 30: 5: 5, volume ratio) and thiophene of total weight) as model compounds to simulate FCC gasoline. The HDS experimental results suggested that the HDS activity and selectivity of Co-Mo / CNTs catalysts were affected by the Co / Mo ratio; the optimal Co / Mo atomic ratio is about 0.4, and the optimum reaction temperature is 260 ° C. The in situ FT-IR studies revealed that 1-octene can be completely saturated at 200 ° C. In the FT-IR spectra of diisobutylene, the characteristic absorption peak around 3081 cm -1 for the stretching vibration peak of = CH bond was still clear at 320 ° C, indicating that dii As the thiophene, no characteristic absorption peak could be found around 3092 cm -1 and 835 cm -1 (when the reaction temperature was raised to 280 ℃, indi-cating that thiophene had been completely hydrodesulfurized. On the basis of FT-IR results, it can be deduced that thiopbene HDS reaction occurred mainly through direct hydrogenolysis route, but thiophene HDS and diisobutylene hydrogenation reaction over Co-Mo / CNTs catalysts might occur on two different kinds of active sites.