Two mixed-matrix NiMo/Al2O3 catalysts containing nano-and micro-sized zeolite Y have been prepared to explore the size effect of zeolite Y particle on the hydrodesulfurization(HDS)and hydrodenitrogenation(HDN)acti...Two mixed-matrix NiMo/Al2O3 catalysts containing nano-and micro-sized zeolite Y have been prepared to explore the size effect of zeolite Y particle on the hydrodesulfurization(HDS)and hydrodenitrogenation(HDN)activities of fluid catalytic cracking(FCC)diesel.They were characterized by SEM,BET,XRD,H2-TPR,NH3-TPD and HRTEM.The results show that the catalyst containing nano-sized zeolite Y possesses larger average pore diameter,higher pore volume,weaker and lesser acid sites,more easily reducible metal phases,shorter MoS2 slabs and more slab layers than the catalyst containing micro-sized zeolite Y.The catalysts were also evaluated with a high-pressure fixed-bed reactor using real FCC diesel as feed.The results display that the catalyst containing nano-sized zeolite Y bears higher HDS and HDN activities and exhibits higher relative rate constant for the removal of total sulfur or nitrogen than the one containing micro-sized zeolite.展开更多
An evidence for the synergetic effect between the stacked bed of Mo/γ-Al2O3 and Ni/γ-Al2O3 in the hydrodenitrogenation (HDN) reaction of quinoline has been provided in this paper. The synergism factor decreases wh...An evidence for the synergetic effect between the stacked bed of Mo/γ-Al2O3 and Ni/γ-Al2O3 in the hydrodenitrogenation (HDN) reaction of quinoline has been provided in this paper. The synergism factor decreases when the reaction temperature increases (280?340 ?C). The synergetic effect leads to improve the hydrogenation activity for the stacked bed compared with the single Mo/γ-Al2O3 bed, which may be attributed to the generation of hydrogen spillover on the Ni/γ-Al2O3 catalyst.展开更多
The charge distribution on Ni-Mo-S active sites can affect hydrodenitrogenation(HDN)activity.In this study,a series of model Ni-Mo-S were developed with various charge distributions.For comparison,the charge distribut...The charge distribution on Ni-Mo-S active sites can affect hydrodenitrogenation(HDN)activity.In this study,a series of model Ni-Mo-S were developed with various charge distributions.For comparison,the charge distribution effects on quinoline HDN were studied.The results show that a lack of electrons and extra protons can both lower the orbital eigenvalue of the Ni-Mo-S,leading to stronger adsorption of nitrogen-containing compounds and inhibition of ammonia desorption.Electron deficiency will improve the generation of active hydrogen on the active sites but inhibit hydrogen transfer to the nitrogen compounds;extra protons can provide H^(+)to the nitrogen compounds,which will flexibly transfer between the nitrogen compound and active sites,thus improving the cleavage of the C-N bond.展开更多
The catalysts were prepared by the temperature programmed reaction (TPR) of MoO3 with NH3 at various temperatures in the range of 573K~973K, and their hydrodenitrogenation (HDN) activities were tested in situ.It is s...The catalysts were prepared by the temperature programmed reaction (TPR) of MoO3 with NH3 at various temperatures in the range of 573K~973K, and their hydrodenitrogenation (HDN) activities were tested in situ.It is shown that molybdenum nitrid(Mo2N) was formed above 923K and its intermediate MoO2 formed at about 573~623K under the rapid (5K/min.) TPR conditions.Mo2N is the most active species for pyridine HDN among MoO3,MoO2,MoS2,and Mo2N. Moreover,it can be promoted by adding Ni component.It is shown that the Ni/Mo2N catalyst prepared by adding some NiO into the precursor MoO3 has a steady HDN activity Which is far higher than that of the commercial sulfided NiMo/Al2O3(HR346) catalyst.展开更多
Catalyst particle shapes and pore structure engineering are crucial for alleviating internal diffusion limitations in the hydrodesulfiirization(HDS)/hydrodeni-trogenation(HDN)of gas oil.The effects of catalyst particl...Catalyst particle shapes and pore structure engineering are crucial for alleviating internal diffusion limitations in the hydrodesulfiirization(HDS)/hydrodeni-trogenation(HDN)of gas oil.The effects of catalyst particle shapes(sphere,cylinder,trilobe,and tetralobe)and pore structures(pore diameter and porosity)on HDS/HDN performance at the particle scale are investigated via mathematical modeling.The relationship between particle shape and effectiveness factor is first established,and the specific surface areas of different catalyst particles show a positive correlation with the average HDS/HDN reaction rates.The catalyst particle shapes primarily alter the average HDS/HDN reaction rate to adjust the HDS/HDN effectiveness factor.An optimal average HDS/HDN reaction rate exists as the catalyst pore diameter and porosity increase,and this optimum value indicates a tradeoff between diffusion and reaction.In contrast to catalyst particle shapes,the catalyst pore diameter and the porosity of catalyst particles primarily alter the surface HDS/HDN reaction rate to adjust the HDS/HDN effectiveness factor.This study provides insights into the engineering of catalyst particle shapes and pore structures for improving HDS/HDN catalyst particle efficiency.展开更多
The Ni2P promoted and γ-Al2O3 supported NiMoW sulfide catalyst consisting of 4 wt% Mo, 22 wt% W, 2 wt% Ni and 2.5 wt% Ni2P was synthesized by a co-impregnation method. The catalysts were characterized by N2 adsorptio...The Ni2P promoted and γ-Al2O3 supported NiMoW sulfide catalyst consisting of 4 wt% Mo, 22 wt% W, 2 wt% Ni and 2.5 wt% Ni2P was synthesized by a co-impregnation method. The catalysts were characterized by N2 adsorption-desorption, X-ray diffraction (XRD), diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy, NH3 temperature-programmed desorption (NH3-TPD) and transmission electron microscopy (TEM). The results showed that Ni2P, Ni, Mo and W species were highly dispersed over γ-Al2O3. The hydrodesulfurization (HDS) of dibenzothiophene (DBT) showed that the presence of Ni2P brought a strong promotional effect on the HDS activity, which was further confirmed by the HDS and hydrodenitrogenation (HDN) of diesel oil under industrial conditions. The enhancement in HDN activity and stability by Ni2P addition could be attributed more to the effect of new active sites of Ni2P than that of acidity modification. The as-prepared Ni2P-NiMoW/γ-Al2O3 catalyst showed better hydrotreating performance than NiMoW/γ-Al2O3 and commercial catalysts.展开更多
A series of supported molybdenum phosphide catalysts were prepared by impregnation method. XRD, TG-DTG, XPS and BET were used to study the phase, compositions and surface areas of the prepared catalysts. A model react...A series of supported molybdenum phosphide catalysts were prepared by impregnation method. XRD, TG-DTG, XPS and BET were used to study the phase, compositions and surface areas of the prepared catalysts. A model reactant containing thiophene, pyridine and cyclohexene was used for the measurements of catalytic activities. The effect of reduction temperature on catalytic activities was investigated. The analysis results by XRD and BET are very different when the reduction temperature is changed from 400 to 900 ℃. MoP/γ-Al2O3 catalysts and CoMoP/γ-Al2O3 catalysts prepared at the reduction temperature of 500 ℃ are the most active ones.展开更多
Supported tungsten phosphide catalysts were prepared by temperature-programmed reduction of their precursors(supported phospho-tungstate catalysts)in H2 and characterized by X-ray diffraction(XRD),BET,temperature-prog...Supported tungsten phosphide catalysts were prepared by temperature-programmed reduction of their precursors(supported phospho-tungstate catalysts)in H2 and characterized by X-ray diffraction(XRD),BET,temperature-programmed desorption of ammonia(NH3-TPD)and X-ray photoelectron spectroscopy(XPS).The reduction-phosphiding processes of the precursors were investigated by thermogravimetry and differential thermal analysis(TG-DTA)and the suitable phosphiding temperatures were defined.The hydrodesulfurization(HDS)and hydrodenitrogenation(HDN)activities of the catalysts were tested by using thiophene,pyridine,dibenzothiophene,carbazole and diesel oil as the feedstock.The TiO2,c-Al_(2)O_(3) supports and the Ni,Co promoters could remarkably increase and stabilize active W species on the catalyst surface.A suitable amount of Ni(3%–5%),Co(5%–7%)and V(1%–3%)could increase dispersivity of the W species and the BET surface area of the WP/c-Al_(2)O_(3) catalyst.The WP/c-Al_(2)O_(3) catalyst possesses much higher thiophene HDS and carbazole HDN activities and the WP/TiO2 catalyst has much higher dibenzothiophene(DBT)HDS and pyridine HDN activities.The Ni,Co and V can obviously promote the HDS activity and inhibit the HDN activity of the WP/c-Al_(2)O_(3) catalyst.The G-Ni5 catalyst possesses a much higher diesel oil HDS activity than the sulphided industrial NiW/c-Al_(2)O_(3) catalyst.In general,a support or promoter in the WP/c-Al_(2)O_(3) catalyst which can increase the amount and dispersivity of the active W species can promote its HDS and HDN activities.展开更多
Mesoporous NiMoAl catalysts with boron phosphate(BPO4)modification were synthesized through the complete liquid-phase method.X-ray diffraction(XRD)analysis evidenced the presence of BPO4-AlOOH mixed support in these B...Mesoporous NiMoAl catalysts with boron phosphate(BPO4)modification were synthesized through the complete liquid-phase method.X-ray diffraction(XRD)analysis evidenced the presence of BPO4-AlOOH mixed support in these BPO4-modified NiMoAl samples.The total amount of acid sites declined,but the surface acidity was strengthened by adding BPO4 into the NiMoAl catalyst.It’s worth noting that the incorporation of BPO4 could increase the concentrations of Ni and Mo species on the catalyst surface and greatly improve the dispersion of(Ni)MoS2 active phases,as indicated by X-ray photoelectron spectroscopy(XPS)and transmission electron microscopy(TEM)measurements.The catalytic performance of these BPO_(4)-modified NiMoAl catalysts was investigated with the hydroprocessing of fluid catalytic cracking(FCC)slurry oil.The nitrogen-containing compounds removal from the oil was significantly enhanced with increasing the molar ratio of boron phosphate/aluminum.The NM-BPA(0.55)catalyst exhibited the best hydrodenitrogenation(HDN)activity,highlighting the significant impact of Mo sulfidation degree and the dispersion of active metals on HDN performance.The introduction of boron phosphate could also promote the hydrocracking activity of the NiMoAl catalyst,as demonstrated by SARA analysis and simulated distillation of liquid products.展开更多
基金financially supported by the Basic Research Program'Green Chemistry and Engineering of Heavy Oil Conversion with High Efficiency' and the National Key Fundamental Research Development Project(973 Project:No.2010CB226905)
文摘Two mixed-matrix NiMo/Al2O3 catalysts containing nano-and micro-sized zeolite Y have been prepared to explore the size effect of zeolite Y particle on the hydrodesulfurization(HDS)and hydrodenitrogenation(HDN)activities of fluid catalytic cracking(FCC)diesel.They were characterized by SEM,BET,XRD,H2-TPR,NH3-TPD and HRTEM.The results show that the catalyst containing nano-sized zeolite Y possesses larger average pore diameter,higher pore volume,weaker and lesser acid sites,more easily reducible metal phases,shorter MoS2 slabs and more slab layers than the catalyst containing micro-sized zeolite Y.The catalysts were also evaluated with a high-pressure fixed-bed reactor using real FCC diesel as feed.The results display that the catalyst containing nano-sized zeolite Y bears higher HDS and HDN activities and exhibits higher relative rate constant for the removal of total sulfur or nitrogen than the one containing micro-sized zeolite.
基金supported by the State Key Development Program for Basic Research of China (No. 2010CB226905)supported by the Basic Research Program " Green Chemistry and Engineering of Heavy Oil Conversionwith High Efficiency "
文摘An evidence for the synergetic effect between the stacked bed of Mo/γ-Al2O3 and Ni/γ-Al2O3 in the hydrodenitrogenation (HDN) reaction of quinoline has been provided in this paper. The synergism factor decreases when the reaction temperature increases (280?340 ?C). The synergetic effect leads to improve the hydrogenation activity for the stacked bed compared with the single Mo/γ-Al2O3 bed, which may be attributed to the generation of hydrogen spillover on the Ni/γ-Al2O3 catalyst.
基金the financial support from the Sinopec Science and Technology Department(Grant No.121014-1)。
文摘The charge distribution on Ni-Mo-S active sites can affect hydrodenitrogenation(HDN)activity.In this study,a series of model Ni-Mo-S were developed with various charge distributions.For comparison,the charge distribution effects on quinoline HDN were studied.The results show that a lack of electrons and extra protons can both lower the orbital eigenvalue of the Ni-Mo-S,leading to stronger adsorption of nitrogen-containing compounds and inhibition of ammonia desorption.Electron deficiency will improve the generation of active hydrogen on the active sites but inhibit hydrogen transfer to the nitrogen compounds;extra protons can provide H^(+)to the nitrogen compounds,which will flexibly transfer between the nitrogen compound and active sites,thus improving the cleavage of the C-N bond.
文摘The catalysts were prepared by the temperature programmed reaction (TPR) of MoO3 with NH3 at various temperatures in the range of 573K~973K, and their hydrodenitrogenation (HDN) activities were tested in situ.It is shown that molybdenum nitrid(Mo2N) was formed above 923K and its intermediate MoO2 formed at about 573~623K under the rapid (5K/min.) TPR conditions.Mo2N is the most active species for pyridine HDN among MoO3,MoO2,MoS2,and Mo2N. Moreover,it can be promoted by adding Ni component.It is shown that the Ni/Mo2N catalyst prepared by adding some NiO into the precursor MoO3 has a steady HDN activity Which is far higher than that of the commercial sulfided NiMo/Al2O3(HR346) catalyst.
基金the National Natural Science Foundation of China(Grant Nos.22038003,21922803,22178100 and 21776077)the Innovation Program of Shanghai Municipal Education Commission,the Program of Shanghai Academic/Technology Research Leader(Grant No.21XD1421000).
文摘Catalyst particle shapes and pore structure engineering are crucial for alleviating internal diffusion limitations in the hydrodesulfiirization(HDS)/hydrodeni-trogenation(HDN)of gas oil.The effects of catalyst particle shapes(sphere,cylinder,trilobe,and tetralobe)and pore structures(pore diameter and porosity)on HDS/HDN performance at the particle scale are investigated via mathematical modeling.The relationship between particle shape and effectiveness factor is first established,and the specific surface areas of different catalyst particles show a positive correlation with the average HDS/HDN reaction rates.The catalyst particle shapes primarily alter the average HDS/HDN reaction rate to adjust the HDS/HDN effectiveness factor.An optimal average HDS/HDN reaction rate exists as the catalyst pore diameter and porosity increase,and this optimum value indicates a tradeoff between diffusion and reaction.In contrast to catalyst particle shapes,the catalyst pore diameter and the porosity of catalyst particles primarily alter the surface HDS/HDN reaction rate to adjust the HDS/HDN effectiveness factor.This study provides insights into the engineering of catalyst particle shapes and pore structures for improving HDS/HDN catalyst particle efficiency.
基金supported by the PetroChina Innovation Foundation (2009D-5006-04-01)Petro China Company Limited of Science and Tech-nology (2008-B-3104-01-01)
文摘The Ni2P promoted and γ-Al2O3 supported NiMoW sulfide catalyst consisting of 4 wt% Mo, 22 wt% W, 2 wt% Ni and 2.5 wt% Ni2P was synthesized by a co-impregnation method. The catalysts were characterized by N2 adsorption-desorption, X-ray diffraction (XRD), diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy, NH3 temperature-programmed desorption (NH3-TPD) and transmission electron microscopy (TEM). The results showed that Ni2P, Ni, Mo and W species were highly dispersed over γ-Al2O3. The hydrodesulfurization (HDS) of dibenzothiophene (DBT) showed that the presence of Ni2P brought a strong promotional effect on the HDS activity, which was further confirmed by the HDS and hydrodenitrogenation (HDN) of diesel oil under industrial conditions. The enhancement in HDN activity and stability by Ni2P addition could be attributed more to the effect of new active sites of Ni2P than that of acidity modification. The as-prepared Ni2P-NiMoW/γ-Al2O3 catalyst showed better hydrotreating performance than NiMoW/γ-Al2O3 and commercial catalysts.
文摘A series of supported molybdenum phosphide catalysts were prepared by impregnation method. XRD, TG-DTG, XPS and BET were used to study the phase, compositions and surface areas of the prepared catalysts. A model reactant containing thiophene, pyridine and cyclohexene was used for the measurements of catalytic activities. The effect of reduction temperature on catalytic activities was investigated. The analysis results by XRD and BET are very different when the reduction temperature is changed from 400 to 900 ℃. MoP/γ-Al2O3 catalysts and CoMoP/γ-Al2O3 catalysts prepared at the reduction temperature of 500 ℃ are the most active ones.
基金State Key Development Basic Research of China(Grant No.G2000048003)the National Natural Science Foundation of China(Grant No.200273011)China Petrochemical Corporation(X501022).
文摘Supported tungsten phosphide catalysts were prepared by temperature-programmed reduction of their precursors(supported phospho-tungstate catalysts)in H2 and characterized by X-ray diffraction(XRD),BET,temperature-programmed desorption of ammonia(NH3-TPD)and X-ray photoelectron spectroscopy(XPS).The reduction-phosphiding processes of the precursors were investigated by thermogravimetry and differential thermal analysis(TG-DTA)and the suitable phosphiding temperatures were defined.The hydrodesulfurization(HDS)and hydrodenitrogenation(HDN)activities of the catalysts were tested by using thiophene,pyridine,dibenzothiophene,carbazole and diesel oil as the feedstock.The TiO2,c-Al_(2)O_(3) supports and the Ni,Co promoters could remarkably increase and stabilize active W species on the catalyst surface.A suitable amount of Ni(3%–5%),Co(5%–7%)and V(1%–3%)could increase dispersivity of the W species and the BET surface area of the WP/c-Al_(2)O_(3) catalyst.The WP/c-Al_(2)O_(3) catalyst possesses much higher thiophene HDS and carbazole HDN activities and the WP/TiO2 catalyst has much higher dibenzothiophene(DBT)HDS and pyridine HDN activities.The Ni,Co and V can obviously promote the HDS activity and inhibit the HDN activity of the WP/c-Al_(2)O_(3) catalyst.The G-Ni5 catalyst possesses a much higher diesel oil HDS activity than the sulphided industrial NiW/c-Al_(2)O_(3) catalyst.In general,a support or promoter in the WP/c-Al_(2)O_(3) catalyst which can increase the amount and dispersivity of the active W species can promote its HDS and HDN activities.
基金This work was supported by the National Natural Science Foundation of China(21808155)the National Key R&D Program of China(2018YFB0604600-01).
文摘Mesoporous NiMoAl catalysts with boron phosphate(BPO4)modification were synthesized through the complete liquid-phase method.X-ray diffraction(XRD)analysis evidenced the presence of BPO4-AlOOH mixed support in these BPO4-modified NiMoAl samples.The total amount of acid sites declined,but the surface acidity was strengthened by adding BPO4 into the NiMoAl catalyst.It’s worth noting that the incorporation of BPO4 could increase the concentrations of Ni and Mo species on the catalyst surface and greatly improve the dispersion of(Ni)MoS2 active phases,as indicated by X-ray photoelectron spectroscopy(XPS)and transmission electron microscopy(TEM)measurements.The catalytic performance of these BPO_(4)-modified NiMoAl catalysts was investigated with the hydroprocessing of fluid catalytic cracking(FCC)slurry oil.The nitrogen-containing compounds removal from the oil was significantly enhanced with increasing the molar ratio of boron phosphate/aluminum.The NM-BPA(0.55)catalyst exhibited the best hydrodenitrogenation(HDN)activity,highlighting the significant impact of Mo sulfidation degree and the dispersion of active metals on HDN performance.The introduction of boron phosphate could also promote the hydrocracking activity of the NiMoAl catalyst,as demonstrated by SARA analysis and simulated distillation of liquid products.