n-Alkane isomerization is a critical reaction that can affect parameters in oil refining, such as the gasoline octane number and diesel oil solidifying point. In this study, a catalyst support, mordenite (MOR)/silicoa...n-Alkane isomerization is a critical reaction that can affect parameters in oil refining, such as the gasoline octane number and diesel oil solidifying point. In this study, a catalyst support, mordenite (MOR)/silicoaluminophosphate (SAPO)-11 composite zeolite with core/shell structure, was synthesized by hydrothermal method with MOR acting as the seed for crystallization. The crystal structure, elemental composition, surface area, pore volume, and acidity of the catalyst was thoroughly characterized. In addition, the catalytic performance of the as-obtained Pt/MOR/SAPO-11 in the hydroisomerization of n-dodecane was tested. The results indicated that the properties and catalytic performance of the composite molecular sieve were quite different from those of the pure zeolites and physical mixture of MOR and SAPO-11 (MOR+SAPO-11). Compared with the physical mixture, MOR and SAPO-11 were more tightly bound in MOR/SAPO-11 because of chemical bonding. Moreover, the acidity and pore structure were favorable to the catalytic hydroisomerization of n-dodecane. Pt/MOR/SAPO-11 exhibited higher isomerization activity than the Pt-loaded pristine MOR and MOR+SAPO-11. Thus, the core-shell composite molecular sieve has promising industrial applications as the catalyst support.展开更多
The Ni/ZnO desulfurization catalyst has been highly valued for its high desulfurization rate and low octane value loss. However, during the process of desulfurization, ZnO is prone to deactivation and the active compo...The Ni/ZnO desulfurization catalyst has been highly valued for its high desulfurization rate and low octane value loss. However, during the process of desulfurization, ZnO is prone to deactivation and the active component Ni is susceptible to agglomeration, which can affect the performance of the catalyst. In order to solve these problems, the modification of ZnO support has been extensively studied. The granular, short rod-shaped and nanowire-structured ZnO were synthesized by controlling the concentration of NaOH, and the desulfurization catalyst was prepared with ZnO serving as the support after loading of metallic Ni. The catalyst was characterized by X-ray diffraction, N2 adsorption-desorption, SEM, TEM and other analytical methods. The desulfurization performance of the catalyst was investigated with n-heptane - thiophene used as model compounds. Test results showed that the morphology and size of ZnO support has great influence on the desulfurization performance of the catalyst. Desulfurization catalyst prepared with nanowire-structured ZnO support has the best desulfurization performance, with its desulfurization rate reaching 98.2%. The result was achieved mainly due to the nanowire structure of ZnO support which could effectively restrain the agglomeration of metallic Ni on the surface and reduce the particle size of the active component of metallic Ni so as to improve its dispersion on the surface of the support. In addition, the nanowire structure can reduce the diffusion resistance of thiophene in the reaction process and provide a channel conducive to sulfur transfer and diffusion, which makes it perform well in the desulphurization reaction process and regeneration process.展开更多
Silicoaluminophosphates SAPO-11 molecular sieves with small particle size and hierarchical pores were synthesized using the directing agent method.The effect of crystallization time on the particle structure,morpholog...Silicoaluminophosphates SAPO-11 molecular sieves with small particle size and hierarchical pores were synthesized using the directing agent method.The effect of crystallization time on the particle structure,morphology,pore structure properties,and acid properties of SAPO-11 molecular sieves were investigated.Unlike the SAPO-11 molecular sieves synthesized with the conventional method,the results of XRD,SEM,BET and NH3-TPD analyses showed that the SAPO-11 molecular sieves synthesized by the directing agent method in a shorter crystallization time exhibited fine and uniform morphology.By increasing the crystallization time,the particle size of SAPO-11 molecular sieve was significantly reduced,and the mesoporous structure(intercrystalline pores)was formed.Furthermore,the external specific surface area and the total specific surface area reached 81.7 m^2/g and 192.0 m^2/g,respectively,which effectively reduced the pore mass transfer resistance and significantly increased the number of acid sites.The results of n-dodecane hydroisomerization revealed that the Pt/SAPO-11 prepared with the novel method exhibited higher catalytic activity and better hydroisomerization selectivity than that synthesized by the conventional hydrothermal method.Thus,the small particle molecular sieve showed a promising industrial application prospect to be used as catalyst support.展开更多
Nanostructured LiFePO4/C cathode material was prepared by FePO4·2H2O/C precursor by in situ restriction reaction.The synthesized LiFePO4/C cathode material presents a narrow distribution of nano-sized particles a...Nanostructured LiFePO4/C cathode material was prepared by FePO4·2H2O/C precursor by in situ restriction reaction.The synthesized LiFePO4/C cathode material presents a narrow distribution of nano-sized particles and exhibits an excellent electrochemical property with various rates.The facile synthesis route for the preparation of nano-sized LiFePO4 material has the particular advantage of simple synthesis process and low synthesis cost.展开更多
基金the National Natural Science Fund of China (2016-Z0030)the Natural Science Foundation of Liaoning Province (L2017LQN008, L2016020)the Fushun Science & Technology Program (2011ZX05039-003)
文摘n-Alkane isomerization is a critical reaction that can affect parameters in oil refining, such as the gasoline octane number and diesel oil solidifying point. In this study, a catalyst support, mordenite (MOR)/silicoaluminophosphate (SAPO)-11 composite zeolite with core/shell structure, was synthesized by hydrothermal method with MOR acting as the seed for crystallization. The crystal structure, elemental composition, surface area, pore volume, and acidity of the catalyst was thoroughly characterized. In addition, the catalytic performance of the as-obtained Pt/MOR/SAPO-11 in the hydroisomerization of n-dodecane was tested. The results indicated that the properties and catalytic performance of the composite molecular sieve were quite different from those of the pure zeolites and physical mixture of MOR and SAPO-11 (MOR+SAPO-11). Compared with the physical mixture, MOR and SAPO-11 were more tightly bound in MOR/SAPO-11 because of chemical bonding. Moreover, the acidity and pore structure were favorable to the catalytic hydroisomerization of n-dodecane. Pt/MOR/SAPO-11 exhibited higher isomerization activity than the Pt-loaded pristine MOR and MOR+SAPO-11. Thus, the core-shell composite molecular sieve has promising industrial applications as the catalyst support.
基金financially supported by the National Natural Science Foundation of China (21401093)
文摘The Ni/ZnO desulfurization catalyst has been highly valued for its high desulfurization rate and low octane value loss. However, during the process of desulfurization, ZnO is prone to deactivation and the active component Ni is susceptible to agglomeration, which can affect the performance of the catalyst. In order to solve these problems, the modification of ZnO support has been extensively studied. The granular, short rod-shaped and nanowire-structured ZnO were synthesized by controlling the concentration of NaOH, and the desulfurization catalyst was prepared with ZnO serving as the support after loading of metallic Ni. The catalyst was characterized by X-ray diffraction, N2 adsorption-desorption, SEM, TEM and other analytical methods. The desulfurization performance of the catalyst was investigated with n-heptane - thiophene used as model compounds. Test results showed that the morphology and size of ZnO support has great influence on the desulfurization performance of the catalyst. Desulfurization catalyst prepared with nanowire-structured ZnO support has the best desulfurization performance, with its desulfurization rate reaching 98.2%. The result was achieved mainly due to the nanowire structure of ZnO support which could effectively restrain the agglomeration of metallic Ni on the surface and reduce the particle size of the active component of metallic Ni so as to improve its dispersion on the surface of the support. In addition, the nanowire structure can reduce the diffusion resistance of thiophene in the reaction process and provide a channel conducive to sulfur transfer and diffusion, which makes it perform well in the desulphurization reaction process and regeneration process.
基金We thank the National Natural Science Fund of China(2016-Z0030)Natural Science Foundation of Liaoning Province(L2017 LQN008,L2019014).
文摘Silicoaluminophosphates SAPO-11 molecular sieves with small particle size and hierarchical pores were synthesized using the directing agent method.The effect of crystallization time on the particle structure,morphology,pore structure properties,and acid properties of SAPO-11 molecular sieves were investigated.Unlike the SAPO-11 molecular sieves synthesized with the conventional method,the results of XRD,SEM,BET and NH3-TPD analyses showed that the SAPO-11 molecular sieves synthesized by the directing agent method in a shorter crystallization time exhibited fine and uniform morphology.By increasing the crystallization time,the particle size of SAPO-11 molecular sieve was significantly reduced,and the mesoporous structure(intercrystalline pores)was formed.Furthermore,the external specific surface area and the total specific surface area reached 81.7 m^2/g and 192.0 m^2/g,respectively,which effectively reduced the pore mass transfer resistance and significantly increased the number of acid sites.The results of n-dodecane hydroisomerization revealed that the Pt/SAPO-11 prepared with the novel method exhibited higher catalytic activity and better hydroisomerization selectivity than that synthesized by the conventional hydrothermal method.Thus,the small particle molecular sieve showed a promising industrial application prospect to be used as catalyst support.
基金supported by the Opening Funds of State Key Lab of Chemical Resource Engineering,Scientific Research Foundation of Liaoning Province for the Fresh Ph.D Graduate (20111061)
文摘Nanostructured LiFePO4/C cathode material was prepared by FePO4·2H2O/C precursor by in situ restriction reaction.The synthesized LiFePO4/C cathode material presents a narrow distribution of nano-sized particles and exhibits an excellent electrochemical property with various rates.The facile synthesis route for the preparation of nano-sized LiFePO4 material has the particular advantage of simple synthesis process and low synthesis cost.