Advanced integrated gasification combined cycle （IGCC） power generation systems require the development of high-temperature, regenerable, desulfurization sorbents capable of removing hydrogen sulfide from coal gasif...Advanced integrated gasification combined cycle （IGCC） power generation systems require the development of high-temperature, regenerable, desulfurization sorbents capable of removing hydrogen sulfide from coal gasifier gas to very low levels. As a sort of effective desufurizer, such as Fe2O3, ZnO and ZnFe2O4, it will endure strong reducing atmosphere in desulfurization process. The reduced degree of desufurizer can have an effect on its desulfurization reactivity. In this paper, Fe2O3, ZnO and ZnFe2O4 were synthesized by precipitation or co-precipitation at constant pH. After aging, washing and drying, the solids were calcined at 800℃. The reduction behaviors of sample were characterized by temperature-programmed reduction （TPR）. It is found that there are two reduction peaks for Fe2O3 in TPR, and whereas no reduction peaks for ZnO are found. The reduction process of ZnFe2O4 prepared by co-precipitation is different from that of Fe2O3. ZnFe2O4 is easier to be reduced than Fe2O3. The activation energy of reduction process for Fe2O3 and ZnFe2O4 is obtained at different reduction periods.展开更多
Fe ions of dose 8×10^16 cm^-2 are implanted into a ZnO single crystal at 180 keV. Annealing at 1073 K leads to the formation of zinc ferrite （ZnFe2O4）, which is verified by synchrotron radiation X-ray diffracti...Fe ions of dose 8×10^16 cm^-2 are implanted into a ZnO single crystal at 180 keV. Annealing at 1073 K leads to the formation of zinc ferrite （ZnFe2O4）, which is verified by synchrotron radiation X-ray diffraction （SR-XRD） and X-ray photoelectron spectroscopy （XPS）. The crystallographically oriented ZnFe2O4 is formed inside the ZnO with the orientation relationship of ZnFe2O4 （111）//ZnO （0001）. Superconducting quantum interference device （SQUID） measurements show that the as-implanted and post-annealing samples are both ferromagnetic at 5 K. The synthesized ZnFe2O4 is superparamagnetic, with a blocking temperature （TB = 25 K）, indicated by zero field cooling and field cooling （ZFC/FC） measurements.展开更多
基金the Ministry of Science and Technology of China under the Grant No. G2005CB221203the Natural Science Foundation of China(20776092)
文摘Advanced integrated gasification combined cycle （IGCC） power generation systems require the development of high-temperature, regenerable, desulfurization sorbents capable of removing hydrogen sulfide from coal gasifier gas to very low levels. As a sort of effective desufurizer, such as Fe2O3, ZnO and ZnFe2O4, it will endure strong reducing atmosphere in desulfurization process. The reduced degree of desufurizer can have an effect on its desulfurization reactivity. In this paper, Fe2O3, ZnO and ZnFe2O4 were synthesized by precipitation or co-precipitation at constant pH. After aging, washing and drying, the solids were calcined at 800℃. The reduction behaviors of sample were characterized by temperature-programmed reduction （TPR）. It is found that there are two reduction peaks for Fe2O3 in TPR, and whereas no reduction peaks for ZnO are found. The reduction process of ZnFe2O4 prepared by co-precipitation is different from that of Fe2O3. ZnFe2O4 is easier to be reduced than Fe2O3. The activation energy of reduction process for Fe2O3 and ZnFe2O4 is obtained at different reduction periods.
基金Project supported by the National Basic Research Program of China (Grant No. 2010CB832904)the National Natural Science Foundation of China (Grant Nos. 10875007 and 11005005)the Research Fund of Shaanxi University of Technology,China(Grant No. SLQ0815)
文摘Fe ions of dose 8×10^16 cm^-2 are implanted into a ZnO single crystal at 180 keV. Annealing at 1073 K leads to the formation of zinc ferrite （ZnFe2O4）, which is verified by synchrotron radiation X-ray diffraction （SR-XRD） and X-ray photoelectron spectroscopy （XPS）. The crystallographically oriented ZnFe2O4 is formed inside the ZnO with the orientation relationship of ZnFe2O4 （111）//ZnO （0001）. Superconducting quantum interference device （SQUID） measurements show that the as-implanted and post-annealing samples are both ferromagnetic at 5 K. The synthesized ZnFe2O4 is superparamagnetic, with a blocking temperature （TB = 25 K）, indicated by zero field cooling and field cooling （ZFC/FC） measurements.
