Novel cobalt Fischer-Tropsch synthesis （FTS） catalysts were prepared from natural halloysite nanotubes （HNT） by double-solvent and wet- impregnation methods, and characterized by TEM, XRD, TPR and N2 adsorption-de...Novel cobalt Fischer-Tropsch synthesis （FTS） catalysts were prepared from natural halloysite nanotubes （HNT） by double-solvent and wet- impregnation methods, and characterized by TEM, XRD, TPR and N2 adsorption-desorption. Comparing with the catalyst prepared by wet- impregnation method, the catalyst prepared by double-solvent method reduces Co3O4 particle migration and agglomeration due to size-induced effect, thus showing higher catalytic activity for Fischer-Tropsch synthesis.展开更多
A Pt-Rh three-way catalyst（M-DS） supported on CeO_2-ZrO_2-La_2O_3-Nd_2O_3 and its analogous supported catalyst（DS） were developed via a modified double-solvent method and conventional double-solvent method, respec...A Pt-Rh three-way catalyst（M-DS） supported on CeO_2-ZrO_2-La_2O_3-Nd_2O_3 and its analogous supported catalyst（DS） were developed via a modified double-solvent method and conventional double-solvent method, respectively. The as-prepared catalysts were characterized by N_2 adsorption-desorption, X-ray diffraction（XRD）, CO-chemisorption, X-ray photoelectron spectroscopy（XPS） and hydrogen temperature-programmed reduction（H_2-TPR）. The preformed Pt nanoparticles generated using ethanol as a reducing agent on M-DS presented enhanced Pt dispersion regardless of aging treatment as confirmed by XRD and CO-chemisorption measurements. The textural properties and reduction ability of M-DS were maintained to a large extent after aging treatment. This result was consistent with those of the N_2 adsorption-desorption and H_2-TPR, respectively. Meanwhile, the XPS analysis demonstrated that higher Pt^0 species and larger Ce^（3＋） concentration could be obtained for M-DS. In the conversion of a simulated compressed natural gas（CNG） vehicle exhaust, both fresh and aged M-DS showed a significant enhancement in the activity and N_2-selectivity. Particularly, the complete conversion temperature（T_（90）） of CH_4 over the aged M-DS catalyst was 65 oC lower than that over the aged catalyst by conventional double-solvent method.展开更多
目的制备苦参碱纳米粒及其麦胚凝集素修饰产物。方法复乳化-溶剂挥发法制备苦参碱纳米粒,以聚乳酸-羟基乙酸共聚物与苦参碱比例、转速和聚乙烯醇浓度为影响因素,粒径、电位、包封率和载药量为评价指标,通过星点设计优化工艺。碳二亚胺...目的制备苦参碱纳米粒及其麦胚凝集素修饰产物。方法复乳化-溶剂挥发法制备苦参碱纳米粒,以聚乳酸-羟基乙酸共聚物与苦参碱比例、转速和聚乙烯醇浓度为影响因素,粒径、电位、包封率和载药量为评价指标,通过星点设计优化工艺。碳二亚胺法制备麦胚凝集素修饰苦参碱纳米粒,以碳二亚胺与N-羟基琥珀酰亚胺比例、麦胚凝集素加入量和孵化时间为影响因素,粒径、电位和修饰率为评价指标,通过均匀设计优化工艺。结果苦参碱纳米粒的最佳条件为聚乳酸-羟基乙酸共聚物与苦参碱比例0.594∶1,转速815 r/min,聚乙烯醇浓度为0.46%,平均粒径、电位、包封率和载药量分别为112.04 nm、-15.38 m V、90.05%和27.14%。其麦胚凝集素修饰产物的最佳条件为碳二亚胺与N-羟基琥珀酰亚胺比例2.8∶0.12,麦胚凝集素加入量3 mg,孵化时间14 h,平均粒径、电位和修饰率分别为474.7 nm、-5.2 m V和69.51%。结论该制备工艺可靠,所得苦参碱纳米粒及其麦胚凝集素修饰产物性质稳定。展开更多
基金supported by the National Natural Science foundation of China (21073238)the National Basic Research Program of China(2011CB211704)the Special Fund for Basic Scientific Research of Central Colleges,South-Central University for Nationalities
文摘Novel cobalt Fischer-Tropsch synthesis （FTS） catalysts were prepared from natural halloysite nanotubes （HNT） by double-solvent and wet- impregnation methods, and characterized by TEM, XRD, TPR and N2 adsorption-desorption. Comparing with the catalyst prepared by wet- impregnation method, the catalyst prepared by double-solvent method reduces Co3O4 particle migration and agglomeration due to size-induced effect, thus showing higher catalytic activity for Fischer-Tropsch synthesis.
基金supported by the National Key Research and Development Program of China(2016YFC0204902)
文摘A Pt-Rh three-way catalyst（M-DS） supported on CeO_2-ZrO_2-La_2O_3-Nd_2O_3 and its analogous supported catalyst（DS） were developed via a modified double-solvent method and conventional double-solvent method, respectively. The as-prepared catalysts were characterized by N_2 adsorption-desorption, X-ray diffraction（XRD）, CO-chemisorption, X-ray photoelectron spectroscopy（XPS） and hydrogen temperature-programmed reduction（H_2-TPR）. The preformed Pt nanoparticles generated using ethanol as a reducing agent on M-DS presented enhanced Pt dispersion regardless of aging treatment as confirmed by XRD and CO-chemisorption measurements. The textural properties and reduction ability of M-DS were maintained to a large extent after aging treatment. This result was consistent with those of the N_2 adsorption-desorption and H_2-TPR, respectively. Meanwhile, the XPS analysis demonstrated that higher Pt^0 species and larger Ce^（3＋） concentration could be obtained for M-DS. In the conversion of a simulated compressed natural gas（CNG） vehicle exhaust, both fresh and aged M-DS showed a significant enhancement in the activity and N_2-selectivity. Particularly, the complete conversion temperature（T_（90）） of CH_4 over the aged M-DS catalyst was 65 oC lower than that over the aged catalyst by conventional double-solvent method.
文摘目的制备苦参碱纳米粒及其麦胚凝集素修饰产物。方法复乳化-溶剂挥发法制备苦参碱纳米粒,以聚乳酸-羟基乙酸共聚物与苦参碱比例、转速和聚乙烯醇浓度为影响因素,粒径、电位、包封率和载药量为评价指标,通过星点设计优化工艺。碳二亚胺法制备麦胚凝集素修饰苦参碱纳米粒,以碳二亚胺与N-羟基琥珀酰亚胺比例、麦胚凝集素加入量和孵化时间为影响因素,粒径、电位和修饰率为评价指标,通过均匀设计优化工艺。结果苦参碱纳米粒的最佳条件为聚乳酸-羟基乙酸共聚物与苦参碱比例0.594∶1,转速815 r/min,聚乙烯醇浓度为0.46%,平均粒径、电位、包封率和载药量分别为112.04 nm、-15.38 m V、90.05%和27.14%。其麦胚凝集素修饰产物的最佳条件为碳二亚胺与N-羟基琥珀酰亚胺比例2.8∶0.12,麦胚凝集素加入量3 mg,孵化时间14 h,平均粒径、电位和修饰率分别为474.7 nm、-5.2 m V和69.51%。结论该制备工艺可靠,所得苦参碱纳米粒及其麦胚凝集素修饰产物性质稳定。
