A selective and efficient process for the electrophilic nitration is described using N_2O_5 as a green nitrating agent,Hβ zeolite as a solid acid catalyst and shape controlling agent under mild conditions.
Modified hierarchical porous Hβ zeolite was obtained by metal modification of Hβ zeolite, which was treated with alkaline solution, and the catalysts before and after modification were characterized by means of X-ra...Modified hierarchical porous Hβ zeolite was obtained by metal modification of Hβ zeolite, which was treated with alkaline solution, and the catalysts before and after modification were characterized by means of X-ray diffraction（XRD）, nitrogen adsorption-desorption~ scanning electron microscopy（SEM）, X-ray fluorescence（XRF）, NH3 temperature-programmed desorption and Fourier-transform infrared spectroscopy（FTIR）. The activities of acy- lation of anisole with acetic anhydride were also investigated. The results show that the Hp zeolite, which was treated with alkaline solution has microporous and mesoporous structures that could improve the diffusion performance of chemical reaction. The amount of acid was modulated with metal modification. The Hβ zeolite modified by 5%（mass fraction） metal chromium had the best catalytic performance. The conversion of acetic anhydride acylation was 93.01% under the optimal conditions, which was higher than that of other catalysts. The catalyst not only showed good activity, but also exhibited a stable performance in regeneration tests.展开更多
ZSM-5/β co-crystalline zeolites with different content of ZSM-5 have beensynthesized by adding different amount of ZSM-5 to the synthetic system of β zeolite with NaAlO_2,silica sol as the source of aluminum and sil...ZSM-5/β co-crystalline zeolites with different content of ZSM-5 have beensynthesized by adding different amount of ZSM-5 to the synthetic system of β zeolite with NaAlO_2,silica sol as the source of aluminum and silica, respectively, and TEA^+ as the template undercontrolled condition of the synthesis. The ZSM-5/β co-crystalline zeolite was studied by XRD, SEM,BET and NH_3-TPD. The reaction activity of toluene alkylation was investigated with a mixture oftoluene-methanol as the feedstock in a pulse micro-reactor over the ZSM-5/β co-crystalline zeolite.It is found that ZSM-5/β co-crystalline zeolite has two kinds of zeolite structure including ZSM-5and β zeolite, not in the form of a physical mixture. The pore structure of ZSM-5/βco-crystalline zeolites is different from that for β zeolite, ZSM-5 and their physical mixture. Inaddition, the peaks of both high and low temperature desorption of ammonia over the ZSM-5/βco-crystalline zeolite shift 23℃ to lower temperatures and the acid amount of its strong acid is 3%more than the physical mixture. So the ZSM-5/β co-crystalline zeolite produces the highest contentof xylene, which is 10.4% higher than the physical mixture. And the ZSM-5/β co-crystalline zeolitehas better selectivity for toluene alkylation and weaker de-methylation than β zeolite, ZSM-5 andtheir physical mixture.展开更多
he effects of reaction temperature , flow rate of carrier gas , space velocity andbenzene to propene ratio on the alkylation of benzene with propene over Hβ zeolitewere investigated. At lower flow rate of carrier gas...he effects of reaction temperature , flow rate of carrier gas , space velocity andbenzene to propene ratio on the alkylation of benzene with propene over Hβ zeolitewere investigated. At lower flow rate of carrier gas and space velocity, higher ben-zene to propene ratio the formation of cumene is favoured due to the difference be-tween rates of reactions of the alkylation of benzene (or cumene) with propene andthe alkyltranslation of diisopropylbenzene with benzene. The propylbenzene is pro-duced directly by the alkylation of benzene with propene.展开更多
基金the financial support from the National Natural Science Foundation of China-Academy of Engineering Physics(No.10976014)the Natural Science Foundation of Jiangsu Province(No.BK2011697)Independent Scientific Research Special Plan of NJUST(No.2011YBXM06)
文摘A selective and efficient process for the electrophilic nitration is described using N_2O_5 as a green nitrating agent,Hβ zeolite as a solid acid catalyst and shape controlling agent under mild conditions.
基金supported by the Natural Science Foundation of China(Granted No.20903080)the Science and Technology Planning Project of Zhejiang Province of China(Granted No.2008C13053)
基金Supported by the Natural Science Foundation of Technology Department of Liaoning Province, China（No.2014020109）.
文摘Modified hierarchical porous Hβ zeolite was obtained by metal modification of Hβ zeolite, which was treated with alkaline solution, and the catalysts before and after modification were characterized by means of X-ray diffraction（XRD）, nitrogen adsorption-desorption~ scanning electron microscopy（SEM）, X-ray fluorescence（XRF）, NH3 temperature-programmed desorption and Fourier-transform infrared spectroscopy（FTIR）. The activities of acy- lation of anisole with acetic anhydride were also investigated. The results show that the Hp zeolite, which was treated with alkaline solution has microporous and mesoporous structures that could improve the diffusion performance of chemical reaction. The amount of acid was modulated with metal modification. The Hβ zeolite modified by 5%（mass fraction） metal chromium had the best catalytic performance. The conversion of acetic anhydride acylation was 93.01% under the optimal conditions, which was higher than that of other catalysts. The catalyst not only showed good activity, but also exhibited a stable performance in regeneration tests.
文摘ZSM-5/β co-crystalline zeolites with different content of ZSM-5 have beensynthesized by adding different amount of ZSM-5 to the synthetic system of β zeolite with NaAlO_2,silica sol as the source of aluminum and silica, respectively, and TEA^+ as the template undercontrolled condition of the synthesis. The ZSM-5/β co-crystalline zeolite was studied by XRD, SEM,BET and NH_3-TPD. The reaction activity of toluene alkylation was investigated with a mixture oftoluene-methanol as the feedstock in a pulse micro-reactor over the ZSM-5/β co-crystalline zeolite.It is found that ZSM-5/β co-crystalline zeolite has two kinds of zeolite structure including ZSM-5and β zeolite, not in the form of a physical mixture. The pore structure of ZSM-5/βco-crystalline zeolites is different from that for β zeolite, ZSM-5 and their physical mixture. Inaddition, the peaks of both high and low temperature desorption of ammonia over the ZSM-5/βco-crystalline zeolite shift 23℃ to lower temperatures and the acid amount of its strong acid is 3%more than the physical mixture. So the ZSM-5/β co-crystalline zeolite produces the highest contentof xylene, which is 10.4% higher than the physical mixture. And the ZSM-5/β co-crystalline zeolitehas better selectivity for toluene alkylation and weaker de-methylation than β zeolite, ZSM-5 andtheir physical mixture.
文摘he effects of reaction temperature , flow rate of carrier gas , space velocity andbenzene to propene ratio on the alkylation of benzene with propene over Hβ zeolitewere investigated. At lower flow rate of carrier gas and space velocity, higher ben-zene to propene ratio the formation of cumene is favoured due to the difference be-tween rates of reactions of the alkylation of benzene (or cumene) with propene andthe alkyltranslation of diisopropylbenzene with benzene. The propylbenzene is pro-duced directly by the alkylation of benzene with propene.
