A series of composite catalysts were prepared by the wet mixing method, and the mass ratio of CuO-ZnO-Al2O3-ZrO2 component to HZSM-5 zeolite （molar ratio of SiO2 to Al2O3 being 25） was 2：1. The CuO-ZnO-Al2O3-ZrO2 ...A series of composite catalysts were prepared by the wet mixing method, and the mass ratio of CuO-ZnO-Al2O3-ZrO2 component to HZSM-5 zeolite （molar ratio of SiO2 to Al2O3 being 25） was 2：1. The CuO-ZnO-Al2O3-ZrO2 （CuO/ZnO/Al2O3=3/6/1 by weight） component was prepared by a modified ＇two-step＇ co-precipitation method. The effects of ZrO2 on the performance of CuO-ZnO-Al2O3/HZSMo5 catalyst for dimethyl ether synthesis from CO2 hydrogenation were investigated. It was found that ZrO2 improved the properties of CuO-ZnO-Al2O3/HZSM-5 as a structural promoter.展开更多
Mo5Si3-20%Al2O3 （mass fraction） nanocomposite was synthesized by mechanical alloying （MA） of mixture of MoO3,Mo,Si and Al powders.The structural evolutions of powder particles during mechanical alloying were studi...Mo5Si3-20%Al2O3 （mass fraction） nanocomposite was synthesized by mechanical alloying （MA） of mixture of MoO3,Mo,Si and Al powders.The structural evolutions of powder particles during mechanical alloying were studied by X-ray diffractometry （XRD）,scanning electron microscopy （SEM）,transmission electron microscopy （TEM） and differential thermal analysis （DTA）.Results show that Mo5Si3-20%Al2O3 was obtained after 10 h of milling.The spontaneous reaction of powders takes place in an explosive mode.The crystallite sizes of Mo5Si3 and Al2O3 after milling for 30 h were 36.3 nm and 21.9 nm,respectively.With longer milling time,the intensities of Mo5Si3 and Al2O3 peaks decreased and became broad due to the decrease in crystallite size.Thermal analysis results and XRD analysis results show that the Mo5Si3-Al2O3 nanocomposite powders are very stable during milling （up to 30 h） and heating （up to 1 000℃） and no transformation takes place.展开更多
文摘A series of composite catalysts were prepared by the wet mixing method, and the mass ratio of CuO-ZnO-Al2O3-ZrO2 component to HZSM-5 zeolite （molar ratio of SiO2 to Al2O3 being 25） was 2：1. The CuO-ZnO-Al2O3-ZrO2 （CuO/ZnO/Al2O3=3/6/1 by weight） component was prepared by a modified ＇two-step＇ co-precipitation method. The effects of ZrO2 on the performance of CuO-ZnO-Al2O3/HZSMo5 catalyst for dimethyl ether synthesis from CO2 hydrogenation were investigated. It was found that ZrO2 improved the properties of CuO-ZnO-Al2O3/HZSM-5 as a structural promoter.
基金Project(3ZS061-A25-038) supported by the Natural Science Foundation of Gansu Province,China
文摘Mo5Si3-20%Al2O3 （mass fraction） nanocomposite was synthesized by mechanical alloying （MA） of mixture of MoO3,Mo,Si and Al powders.The structural evolutions of powder particles during mechanical alloying were studied by X-ray diffractometry （XRD）,scanning electron microscopy （SEM）,transmission electron microscopy （TEM） and differential thermal analysis （DTA）.Results show that Mo5Si3-20%Al2O3 was obtained after 10 h of milling.The spontaneous reaction of powders takes place in an explosive mode.The crystallite sizes of Mo5Si3 and Al2O3 after milling for 30 h were 36.3 nm and 21.9 nm,respectively.With longer milling time,the intensities of Mo5Si3 and Al2O3 peaks decreased and became broad due to the decrease in crystallite size.Thermal analysis results and XRD analysis results show that the Mo5Si3-Al2O3 nanocomposite powders are very stable during milling （up to 30 h） and heating （up to 1 000℃） and no transformation takes place.
