Nanosize cerium-zirconium solid solution(CZO)with a special fluorite structure has received an increasing research interest due to their remarkable advantages such as excellent oxygen storage capacity and great flexib...Nanosize cerium-zirconium solid solution(CZO)with a special fluorite structure has received an increasing research interest due to their remarkable advantages such as excellent oxygen storage capacity and great flexibility in their composition and structure.By partial metal(including rare earth,transition,alkaline earth or other metal)doping into CZO,the physicochemical properties of these catalytic materials can be controllable adjusted for the study of specific reactions.To date,nanosize CZO has been prepared by co-precipitation,sol-gel,surfactant-assisted approach,solution combustion,micro-emulsion,high energy mechanical milling,etc.The advent of these methodologies has prompted researchers to construct well-defined networks with customized micromorphology and functionalities.In this review,we describe not only the basic structure and synthetic strategies of CZO,but also their relevant applications in environmental catalysis,such as the purification for CO,nitrogen oxides(NOx),volatile organic compounds(VOC),soot,hydrocarbon(HC),CO2 and solid particulate matters(PM),and some reaction mechanisms are also summarized.展开更多
CeO2-ZrO2 mixed oxide （Ce0.6Zr0.402） prepared by microwave-assisted heating co-precipitation was used as a support to prepare a series of CuO/Ce0.6Zr0.402 catalysts with various CuO contents （0 wt.%-1 5 wt.%） via ...CeO2-ZrO2 mixed oxide （Ce0.6Zr0.402） prepared by microwave-assisted heating co-precipitation was used as a support to prepare a series of CuO/Ce0.6Zr0.402 catalysts with various CuO contents （0 wt.%-1 5 wt.%） via the method of incipient-wetness im- pregnation. The obtained CuO/Ce0.6Zr0.402 samples were characterized by N2 adsorption, XRD, Raman, TEM and H2-TPR technolo- gies, and their catalytic activities for CO oxidation were investigated. The results showed that the activity of CuO/Ce0.6Zr0.402 catalyst was strongly influenced by the content of CuO, and the catalyst with 10 wt.% CuO exhibited the best catalytic activity in CO oxida- tion, which could be attributed to the high dispersion and reducibility of CuO, and high oxygen vacancy concentration in the catalyst.展开更多
Mesoporous cerium-zirconium mixed oxides were prepared by hydrothermal method using cetyl trimethyl ammonium bromide (CTAB) as template. The effects of amount of template, pH value of solution and hydrothermal tempera...Mesoporous cerium-zirconium mixed oxides were prepared by hydrothermal method using cetyl trimethyl ammonium bromide (CTAB) as template. The effects of amount of template, pH value of solution and hydrothermal temperature on mesostructure of samples were systematically investigated. The final products were characterized by XRD, TEM, FT-IR, and BET. The results indicate that all the cerium-zirconium mixed oxides present a meso-structure. At molar ratio of n(CTAB)/n((Ce)+(Zr))= 0.15, pH value of 9, and hydrothermal temperature of 120 ℃, the samples obtained possess a specific surface area of 207.9 m2/g with pore diameter of 3.70 nm and pore volume of 0.19 cm3/g.展开更多
Cerium-zirconium composite oxides with high performance were synthesized by a co-precipitation method, using zirconium oxychloride and rare earth chloride as raw materials. The effects of precipitate aging time on the...Cerium-zirconium composite oxides with high performance were synthesized by a co-precipitation method, using zirconium oxychloride and rare earth chloride as raw materials. The effects of precipitate aging time on the properties of cerium-zirconium composite oxides were investigated. The prepared cerium-zirconium composite oxides were characterized by X-ray diffraction（XRD）, BET specific surface area, pulsed oxygen chemical adsorption, H2 temperature-programmed-reduction（H2-TPR）, scanning electron microscopy（SEM）, etc. The results showed that the precipitate aging time caused great effects on the properties of cerium zirconium composite oxides. With the increase of aging time, the cerium zirconium composite oxides showed enhanced specific surface area, good thermal stability, and high oxygen storage capacity（OSC）. The best performance sample was obtained while the precipitate aging time up to 48 h, with the specific surface area of 140.7 m2/g, and OSC of 657.24 μmolO2/g for the fresh sample. Even after thermal aged under 1000 oC for 4 h, the aged specific surface area was 41.6 m2/g, moreover with a good OSC of 569.9 μmolO2/g.展开更多
A series of materials Ce0.3+xZr0.6-xY0.1O1.95 were prepared by co-precipitation routine and the property of these materials was studied by means of oxygen storage capacity, temperature programming reduction, X-ray dif...A series of materials Ce0.3+xZr0.6-xY0.1O1.95 were prepared by co-precipitation routine and the property of these materials was studied by means of oxygen storage capacity, temperature programming reduction, X-ray diffraction, transmission electronic microscope, and X-ray photoelectron spectroscopy. The results indicate that the materials with a low Ce/Zr molar ratio possess higher cerium atom utilization ratio, reducibility and thermal stability than the materials with a high Ce/Zr ratio, and Ce0.35Zr0.55Y0.1O1.95 possesses the best properties.展开更多
Nanorod-like Ce0.7Zr0.3O2 solid solutions were synthesized by a sodium dodecyl sulfate-assisted precipitation method. The samples were characterized by means of scanning electron microscopy, transmission electron micr...Nanorod-like Ce0.7Zr0.3O2 solid solutions were synthesized by a sodium dodecyl sulfate-assisted precipitation method. The samples were characterized by means of scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and specific surface area measurement. Typical Ce0.7Zr0.3O2 nanorods were 40 nm in average diameter and 450 nm in length, with specific surface area and oxygen storage capacity of 194 m2/g and 374 μmol/g, respectively.展开更多
基金financially supported by the National Natural Science Foundation of China (21673290, U1662103)~~
文摘Nanosize cerium-zirconium solid solution(CZO)with a special fluorite structure has received an increasing research interest due to their remarkable advantages such as excellent oxygen storage capacity and great flexibility in their composition and structure.By partial metal(including rare earth,transition,alkaline earth or other metal)doping into CZO,the physicochemical properties of these catalytic materials can be controllable adjusted for the study of specific reactions.To date,nanosize CZO has been prepared by co-precipitation,sol-gel,surfactant-assisted approach,solution combustion,micro-emulsion,high energy mechanical milling,etc.The advent of these methodologies has prompted researchers to construct well-defined networks with customized micromorphology and functionalities.In this review,we describe not only the basic structure and synthetic strategies of CZO,but also their relevant applications in environmental catalysis,such as the purification for CO,nitrogen oxides(NOx),volatile organic compounds(VOC),soot,hydrocarbon(HC),CO2 and solid particulate matters(PM),and some reaction mechanisms are also summarized.
基金supported by National Natural Science Foundation of China(21273150)‘‘Shu Guang’’ Project of Shanghai Municipal Education CommissionShanghai Education Development Foundation(10GG23)
文摘CeO2-ZrO2 mixed oxide （Ce0.6Zr0.402） prepared by microwave-assisted heating co-precipitation was used as a support to prepare a series of CuO/Ce0.6Zr0.402 catalysts with various CuO contents （0 wt.%-1 5 wt.%） via the method of incipient-wetness im- pregnation. The obtained CuO/Ce0.6Zr0.402 samples were characterized by N2 adsorption, XRD, Raman, TEM and H2-TPR technolo- gies, and their catalytic activities for CO oxidation were investigated. The results showed that the activity of CuO/Ce0.6Zr0.402 catalyst was strongly influenced by the content of CuO, and the catalyst with 10 wt.% CuO exhibited the best catalytic activity in CO oxida- tion, which could be attributed to the high dispersion and reducibility of CuO, and high oxygen vacancy concentration in the catalyst.
基金Project(CHCL0501) supported by Hubei Provincial Open Fund of Key Laboratory of Catalytic Material Science and Technology
文摘Mesoporous cerium-zirconium mixed oxides were prepared by hydrothermal method using cetyl trimethyl ammonium bromide (CTAB) as template. The effects of amount of template, pH value of solution and hydrothermal temperature on mesostructure of samples were systematically investigated. The final products were characterized by XRD, TEM, FT-IR, and BET. The results indicate that all the cerium-zirconium mixed oxides present a meso-structure. At molar ratio of n(CTAB)/n((Ce)+(Zr))= 0.15, pH value of 9, and hydrothermal temperature of 120 ℃, the samples obtained possess a specific surface area of 207.9 m2/g with pore diameter of 3.70 nm and pore volume of 0.19 cm3/g.
基金Project supported by the Twelfth Five-Year National Science and Technology Pillar Program(2012BAE01B02)National Development and Reform Commission Fund:Development and commercialization of the rare earth based automotive catalytic converter for national V automotive emission standard
文摘Cerium-zirconium composite oxides with high performance were synthesized by a co-precipitation method, using zirconium oxychloride and rare earth chloride as raw materials. The effects of precipitate aging time on the properties of cerium-zirconium composite oxides were investigated. The prepared cerium-zirconium composite oxides were characterized by X-ray diffraction（XRD）, BET specific surface area, pulsed oxygen chemical adsorption, H2 temperature-programmed-reduction（H2-TPR）, scanning electron microscopy（SEM）, etc. The results showed that the precipitate aging time caused great effects on the properties of cerium zirconium composite oxides. With the increase of aging time, the cerium zirconium composite oxides showed enhanced specific surface area, good thermal stability, and high oxygen storage capacity（OSC）. The best performance sample was obtained while the precipitate aging time up to 48 h, with the specific surface area of 140.7 m2/g, and OSC of 657.24 μmolO2/g for the fresh sample. Even after thermal aged under 1000 oC for 4 h, the aged specific surface area was 41.6 m2/g, moreover with a good OSC of 569.9 μmolO2/g.
文摘A series of materials Ce0.3+xZr0.6-xY0.1O1.95 were prepared by co-precipitation routine and the property of these materials was studied by means of oxygen storage capacity, temperature programming reduction, X-ray diffraction, transmission electronic microscope, and X-ray photoelectron spectroscopy. The results indicate that the materials with a low Ce/Zr molar ratio possess higher cerium atom utilization ratio, reducibility and thermal stability than the materials with a high Ce/Zr ratio, and Ce0.35Zr0.55Y0.1O1.95 possesses the best properties.
文摘Nanorod-like Ce0.7Zr0.3O2 solid solutions were synthesized by a sodium dodecyl sulfate-assisted precipitation method. The samples were characterized by means of scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and specific surface area measurement. Typical Ce0.7Zr0.3O2 nanorods were 40 nm in average diameter and 450 nm in length, with specific surface area and oxygen storage capacity of 194 m2/g and 374 μmol/g, respectively.
