A series of P/HZSM-5 catalysts prepared by impregnation method were used for ethanol conversion to lower olefins. The catalysts were characterized by X-ray diffraction （XRD）, NH3-temperature-programmed desorption （...A series of P/HZSM-5 catalysts prepared by impregnation method were used for ethanol conversion to lower olefins. The catalysts were characterized by X-ray diffraction （XRD）, NH3-temperature-programmed desorption （NH3-TPD） and N2 adsorption-desorption measurements. It was found that the P/HZSM-5 catalysts showed high activity and selectivity toward light olefins. The selectivities of propylene and butylene can be improved with the introduction of phosphorus （P）. When the content of P reached 3.0 wt%, more than 18.9% propylene in the gaseous products was obtained over the P/HZSM-5 catalyst at 450 ？C. The introduction of P modified the strong Br？nsted acid sites of the original HZSM-5 catalysts and P/HZSM-5 catalysts could resist coke formation and showed good stability.展开更多
Shape-selective zeolites(UZ-x/y) were synthesized by a one-pot method using TPAOH(y) and/or MeEt3 N^+I^-(x) as templates.The use of MeEt3 N^+I^- affects the crystal growth and the distribution of acid sites on the ext...Shape-selective zeolites(UZ-x/y) were synthesized by a one-pot method using TPAOH(y) and/or MeEt3 N^+I^-(x) as templates.The use of MeEt3 N^+I^- affects the crystal growth and the distribution of acid sites on the external surface of the zeolites.The catalysts show excellent catalytic activity towards toluene alkylation with CH3 Br.With toluene conversion of 36.3% and p-xylene selectivity of 66.2%,HZ-40/0 is the most effective among the prepared catalysts,showing a p-xylene yield of 21.2%.The improved para-selectivity is mainly due to the decrease of acid sites on the external surface of the catalysts.展开更多
基金supported by the Doctor Fund of Science Research of Xinjiang University (Grant No. BS060101)the National Natural ScienceFoundation of China (Grant No. 20963010)
文摘A series of P/HZSM-5 catalysts prepared by impregnation method were used for ethanol conversion to lower olefins. The catalysts were characterized by X-ray diffraction （XRD）, NH3-temperature-programmed desorption （NH3-TPD） and N2 adsorption-desorption measurements. It was found that the P/HZSM-5 catalysts showed high activity and selectivity toward light olefins. The selectivities of propylene and butylene can be improved with the introduction of phosphorus （P）. When the content of P reached 3.0 wt%, more than 18.9% propylene in the gaseous products was obtained over the P/HZSM-5 catalyst at 450 ？C. The introduction of P modified the strong Br？nsted acid sites of the original HZSM-5 catalysts and P/HZSM-5 catalysts could resist coke formation and showed good stability.
基金Supported by the National Natural Science Foundation of China(21273067,21476065,21671062,21725602)Program for Changjiang Scholars and Innovative Research Team in University(IRT1238)the Fundamental Research Funds for the Central Universities
文摘Shape-selective zeolites(UZ-x/y) were synthesized by a one-pot method using TPAOH(y) and/or MeEt3 N^+I^-(x) as templates.The use of MeEt3 N^+I^- affects the crystal growth and the distribution of acid sites on the external surface of the zeolites.The catalysts show excellent catalytic activity towards toluene alkylation with CH3 Br.With toluene conversion of 36.3% and p-xylene selectivity of 66.2%,HZ-40/0 is the most effective among the prepared catalysts,showing a p-xylene yield of 21.2%.The improved para-selectivity is mainly due to the decrease of acid sites on the external surface of the catalysts.
