Perovskite oxides LaCoO3 prepared by templating,co-precipitation and sol-gel method with different complexants were systematically characterized and its catalytic performances for CO oxidation were investigated.The sa...Perovskite oxides LaCoO3 prepared by templating,co-precipitation and sol-gel method with different complexants were systematically characterized and its catalytic performances for CO oxidation were investigated.The samples were characterized by X-ray diffraction,thermogravimetry analysis and differential scanning calorimetry,N2 physisorption,transmission electron microscopy,temperature program reduction of hydrogen,temperature program desorption of oxygen and X-ray photoelectron spectroscopy measurement,results of which show that the properties of LaCoO3,such as surface morphology,surface area,surface compositions,redox capability,oxygen vacancy,as well as the calcination temperature and formation mechanism,depend intimately on the preparation method.Catalytic tests indicate that the sample prepared by carbon templating method shows the best activity for CO oxidation,with full CO conversion obtained at 135℃.In particular,the catalyst can be activated and significant increase of activity can be obtained with the increase of reaction time.The cyclic and longterm stability of catalysts were discussed and compared.展开更多
Spherical carbonyl iron(Fe)powders were coated with magnesioferrite(MgFe2O4)insulating coating layer and then mixed with epoxy-modified silicone resin(ESR).Soft magnetic composites(SMCs)were fabricated by compaction o...Spherical carbonyl iron(Fe)powders were coated with magnesioferrite(MgFe2O4)insulating coating layer and then mixed with epoxy-modified silicone resin(ESR).Soft magnetic composites(SMCs)were fabricated by compaction of the coated powders and annealing treatment.Transmission electron microscopy(TEM),scanning electron microscopy(SEM),energy dispersive spectroscopy(EDS),X-ray diffractometry(XRD)and X-ray photoelectron spectroscopy(XPS)revealed that the MgFe2O4 layer was coated on the surface of the iron powders.The magnetic properties of SMCs were determined using a vibrating sample magnetometer and an auto testing system for magnetic materials.The results showed that the SMCs prepared at 800 MPa and 550℃ exhibited a significant core loss of 167.5 W/kg at 100 kHz and 50 mT.展开更多
基金Project supported by the National Natural Science Foundation of China(21203254)Natural Science Foundation of Hubei Province(2015CFA138)+1 种基金Natural Science Foundation of Liaoning Province(201602681)Shenyang Municipal Science and Technology Planning Projects(17-76-1-00)
文摘Perovskite oxides LaCoO3 prepared by templating,co-precipitation and sol-gel method with different complexants were systematically characterized and its catalytic performances for CO oxidation were investigated.The samples were characterized by X-ray diffraction,thermogravimetry analysis and differential scanning calorimetry,N2 physisorption,transmission electron microscopy,temperature program reduction of hydrogen,temperature program desorption of oxygen and X-ray photoelectron spectroscopy measurement,results of which show that the properties of LaCoO3,such as surface morphology,surface area,surface compositions,redox capability,oxygen vacancy,as well as the calcination temperature and formation mechanism,depend intimately on the preparation method.Catalytic tests indicate that the sample prepared by carbon templating method shows the best activity for CO oxidation,with full CO conversion obtained at 135℃.In particular,the catalyst can be activated and significant increase of activity can be obtained with the increase of reaction time.The cyclic and longterm stability of catalysts were discussed and compared.
基金Project(2016YFB0700302)supported by the National Key Research and Development Program of ChinaProjects(51862030,51563020)supported by the National Natural Science Foundation of China。
文摘Spherical carbonyl iron(Fe)powders were coated with magnesioferrite(MgFe2O4)insulating coating layer and then mixed with epoxy-modified silicone resin(ESR).Soft magnetic composites(SMCs)were fabricated by compaction of the coated powders and annealing treatment.Transmission electron microscopy(TEM),scanning electron microscopy(SEM),energy dispersive spectroscopy(EDS),X-ray diffractometry(XRD)and X-ray photoelectron spectroscopy(XPS)revealed that the MgFe2O4 layer was coated on the surface of the iron powders.The magnetic properties of SMCs were determined using a vibrating sample magnetometer and an auto testing system for magnetic materials.The results showed that the SMCs prepared at 800 MPa and 550℃ exhibited a significant core loss of 167.5 W/kg at 100 kHz and 50 mT.
