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
Adsorption of pure CO_(2) and N2 and separation of CO_(2)/N2 mixture in MFI zeolite and MFI/MCM-41 micro/mesoporous composite have been studied by using atomistic simulations.Fully atomistic models of MFI and MFI/MCM-...Adsorption of pure CO_(2) and N2 and separation of CO_(2)/N2 mixture in MFI zeolite and MFI/MCM-41 micro/mesoporous composite have been studied by using atomistic simulations.Fully atomistic models of MFI and MFI/MCM-41 are constructed and characterized.A bimodal pore size distribution is observed in MFI/MCM-41 from simulated small-and broad-angle X-ray diffrac-tion patterns.The density of MFI/MCM-41 is lower than MFI,while its free volume and specific surface area are greater than MFI due to the presence of mesopores.CO_(2) is preferentially adsorbed than N2,and thus,the loading and isosteric heat of CO_(2) are greater than N2 in both MFI and MFI/MCM-41.CO_(2) isotherm in MFI/MCM-41 is similar to that in MFI at low pressures,but resembles that in MCM-41 at high pressures.N2 shows similar amount of loading in MFI,MCM-41 and MFI/MCM-41.The selectivity of CO_(2) over N2 in the three adsorbents decreases in the order of MFI>MFI/MCM-41>MCM-41.With increasing pressure,the selectivity increases in MFI and MFI/MCM-41,but decreases in MCM-41.The self-diffusivity of CO_(2) and N2 in MFI decreases as loading increases,while in MFI/MCM-41,itfirst increases and then drops.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 National Natural Science Foundation of China(Grant Nos.20736002,20776045)the National High Technology Research and Development Program of China(No.2008AA062302)+1 种基金Program for Changjiang Scholars and Innovative Research Team in University of China(No.IRT0721)the 111 Project of China(No.B08021).
文摘Adsorption of pure CO_(2) and N2 and separation of CO_(2)/N2 mixture in MFI zeolite and MFI/MCM-41 micro/mesoporous composite have been studied by using atomistic simulations.Fully atomistic models of MFI and MFI/MCM-41 are constructed and characterized.A bimodal pore size distribution is observed in MFI/MCM-41 from simulated small-and broad-angle X-ray diffrac-tion patterns.The density of MFI/MCM-41 is lower than MFI,while its free volume and specific surface area are greater than MFI due to the presence of mesopores.CO_(2) is preferentially adsorbed than N2,and thus,the loading and isosteric heat of CO_(2) are greater than N2 in both MFI and MFI/MCM-41.CO_(2) isotherm in MFI/MCM-41 is similar to that in MFI at low pressures,but resembles that in MCM-41 at high pressures.N2 shows similar amount of loading in MFI,MCM-41 and MFI/MCM-41.The selectivity of CO_(2) over N2 in the three adsorbents decreases in the order of MFI>MFI/MCM-41>MCM-41.With increasing pressure,the selectivity increases in MFI and MFI/MCM-41,but decreases in MCM-41.The self-diffusivity of CO_(2) and N2 in MFI decreases as loading increases,while in MFI/MCM-41,itfirst increases and then drops.
