通过水热晶化法,合成含有骨架杂原子Fe的Fe-HZSM-5分子筛催化剂,采用XRD、BET和NH3-TPD对催化剂进行表征,在微型固定床反应器中测定催化剂的甲醇制汽油的反应性能和反应动力学数据,对Fe-HZSM-5分子筛催化剂的甲醇制汽油本征动力学进行...通过水热晶化法,合成含有骨架杂原子Fe的Fe-HZSM-5分子筛催化剂,采用XRD、BET和NH3-TPD对催化剂进行表征,在微型固定床反应器中测定催化剂的甲醇制汽油的反应性能和反应动力学数据,对Fe-HZSM-5分子筛催化剂的甲醇制汽油本征动力学进行研究。结果表明,ZSM-5分子筛骨架引入杂原子Fe,可以增加对产物汽油选择性有利的弱酸量。采用Chen and Reagan建立的甲醇制汽油三集总动力学模型,通过Runge-Kutta法和最小二乘法对实验数据的回归计算,获得反应速率常数为k1=0.921×1012exp(-108 600/RT)、k2=0.155×1012exp(-116 400/RT)和k3=1.008×107exp(-96 130/RT)。以目标残差函数OF参数值为检验模型的标准,模拟值和实验值的相关系数R2均超过0.99。因此,Chen and Reagan建立的甲醇制汽油三集总动力学模型可以准确描述Fe-HZSM-5分子筛催化剂的甲醇制汽油反应动力学行为。展开更多
A series of Fe/HZSM-5 catalysts with different iron loadings were prepared by impregnation method.Characterization was performed by N2 adsorption-desorption,X-ray diffraction（XRD）,NH3 temperature-programmed desorpt...A series of Fe/HZSM-5 catalysts with different iron loadings were prepared by impregnation method.Characterization was performed by N2 adsorption-desorption,X-ray diffraction（XRD）,NH3 temperature-programmed desorption（NH3-TPD）,temperature-programmed reduction （TPR）,temperature-programmed oxidation（TPO）and thermogravimetry（TG）analysis.Iron content in the synthesized samples varied from 1.1 wt%to 20 wt%.The obtained samples have been used for ethanol conversion into light olefins.It was found that the amount of strong acidity at 300 -5 50-C on Fe-modified samples was decreased,going with another new acid site appearance at 550- 600-C and that Fe/HZSM-5 catalysts were highly selective towards light olefins,especially the 9FZ sample.In addition,Fe-modified catalysts suppressed the conversion of ethanol to aromatics and paraffins and enhanced their anti-carbon deposit ability.展开更多
The influence of adding Fe, Cr, Co, and Ga into 3%Mo/HZSM-5 catalyst on methane aromatization, and the influence of additives ratio on methane conversion, selectivity to hydrocarbons and coke, as well as distribution ...The influence of adding Fe, Cr, Co, and Ga into 3%Mo/HZSM-5 catalyst on methane aromatization, and the influence of additives ratio on methane conversion, selectivity to hydrocarbons and coke, as well as distribution of aromatics were investigated. The experimental results showed that the addition of Fe, Cr, Co and Ga promoted the dehydrogenation and dissociation of methane. The results of NH3-TPD indicated that the acidity of HZSM-5 was changed by adding Fe and Co components, consequently the catalytic properties of Mo/HZSM-5 were changed. It was also revealed that strong acid sites were the center of methane aromatization. The results of XRD characterization showed that the crystallinity of Mo on ZSM-5 zeolite was increased after adding Fe, Co additives.展开更多
FeO_x/HZSM-5 catalyst with 8 wt.%Fe-loading（8-FeZ） exhibited significantly higher reactivity in the benzylation of benzene with benzyl chloride than FeO_x/HZSM-5 catalyst with 2.5 wt.%Fe-loading（2.5-FeZ） because t...FeO_x/HZSM-5 catalyst with 8 wt.%Fe-loading（8-FeZ） exhibited significantly higher reactivity in the benzylation of benzene with benzyl chloride than FeO_x/HZSM-5 catalyst with 2.5 wt.%Fe-loading（2.5-FeZ） because the synergistic catalysis between isolated Fe^（3＋） and superfine Fe_2O_3 occurred on 8-FeZ in the reaction.展开更多
文摘通过水热晶化法,合成含有骨架杂原子Fe的Fe-HZSM-5分子筛催化剂,采用XRD、BET和NH3-TPD对催化剂进行表征,在微型固定床反应器中测定催化剂的甲醇制汽油的反应性能和反应动力学数据,对Fe-HZSM-5分子筛催化剂的甲醇制汽油本征动力学进行研究。结果表明,ZSM-5分子筛骨架引入杂原子Fe,可以增加对产物汽油选择性有利的弱酸量。采用Chen and Reagan建立的甲醇制汽油三集总动力学模型,通过Runge-Kutta法和最小二乘法对实验数据的回归计算,获得反应速率常数为k1=0.921×1012exp(-108 600/RT)、k2=0.155×1012exp(-116 400/RT)和k3=1.008×107exp(-96 130/RT)。以目标残差函数OF参数值为检验模型的标准,模拟值和实验值的相关系数R2均超过0.99。因此,Chen and Reagan建立的甲醇制汽油三集总动力学模型可以准确描述Fe-HZSM-5分子筛催化剂的甲醇制汽油反应动力学行为。
基金supported by the National Natural Science Foundation of China(No.20963010)the Doctor Fund of Science Research(No.070267)
文摘A series of Fe/HZSM-5 catalysts with different iron loadings were prepared by impregnation method.Characterization was performed by N2 adsorption-desorption,X-ray diffraction（XRD）,NH3 temperature-programmed desorption（NH3-TPD）,temperature-programmed reduction （TPR）,temperature-programmed oxidation（TPO）and thermogravimetry（TG）analysis.Iron content in the synthesized samples varied from 1.1 wt%to 20 wt%.The obtained samples have been used for ethanol conversion into light olefins.It was found that the amount of strong acidity at 300 -5 50-C on Fe-modified samples was decreased,going with another new acid site appearance at 550- 600-C and that Fe/HZSM-5 catalysts were highly selective towards light olefins,especially the 9FZ sample.In addition,Fe-modified catalysts suppressed the conversion of ethanol to aromatics and paraffins and enhanced their anti-carbon deposit ability.
文摘The influence of adding Fe, Cr, Co, and Ga into 3%Mo/HZSM-5 catalyst on methane aromatization, and the influence of additives ratio on methane conversion, selectivity to hydrocarbons and coke, as well as distribution of aromatics were investigated. The experimental results showed that the addition of Fe, Cr, Co and Ga promoted the dehydrogenation and dissociation of methane. The results of NH3-TPD indicated that the acidity of HZSM-5 was changed by adding Fe and Co components, consequently the catalytic properties of Mo/HZSM-5 were changed. It was also revealed that strong acid sites were the center of methane aromatization. The results of XRD characterization showed that the crystallinity of Mo on ZSM-5 zeolite was increased after adding Fe, Co additives.
基金financially supported by Ministry of Education(No.NCET-10-878,20096101120018,2009-37th of SRFROCS)Shaanxi Province(No.2009ZDKG-70,09JK793)+1 种基金Northwest University(No.PR200905)State Key Lab for SSPC(2009)
文摘FeO_x/HZSM-5 catalyst with 8 wt.%Fe-loading（8-FeZ） exhibited significantly higher reactivity in the benzylation of benzene with benzyl chloride than FeO_x/HZSM-5 catalyst with 2.5 wt.%Fe-loading（2.5-FeZ） because the synergistic catalysis between isolated Fe^（3＋） and superfine Fe_2O_3 occurred on 8-FeZ in the reaction.
