便携式电子产品、电动汽车和储能领域的快速发展对电池能量密度的要求越来越高,正极材料是限制电池能量密度的主要因素。过渡金属氟磷酸盐(A2MPO4F,A=Li、Na,M=Mn、Fe、Co、Ni)是一类高比容量(~300 m A·h/g)和高能量密度(>1000 ...便携式电子产品、电动汽车和储能领域的快速发展对电池能量密度的要求越来越高,正极材料是限制电池能量密度的主要因素。过渡金属氟磷酸盐(A2MPO4F,A=Li、Na,M=Mn、Fe、Co、Ni)是一类高比容量(~300 m A·h/g)和高能量密度(>1000 W·h/kg)的新型正极材料。主要介绍了A2MPO4F的结构、合成方法与改性方面的最新进展。讨论了A2MPO4F所面临的主要挑战,特别是实现两电子反应所面临的困难。展望了它们的应用前景。展开更多
The binary composite photo-catalysts CeO2/ZiO2, ZrO2/ZiO2 and the ternary composite photo-catalysts H3PW12040-CeO2/TiO2, H3PW12O40-ZrO2/TiO2 were prepared by sol-gel method. The catalysts were characterized by thermog...The binary composite photo-catalysts CeO2/ZiO2, ZrO2/ZiO2 and the ternary composite photo-catalysts H3PW12040-CeO2/TiO2, H3PW12O40-ZrO2/TiO2 were prepared by sol-gel method. The catalysts were characterized by thermogravimetric-differential thermal analysis （TG-DTA）, scanning electron microscopy （SEM） and X-ray diffraction （XRD）. The photocatalytic elimination of methanol was used as model reaction to evaluate the photocatalytic activity of the composite catalysts under ultraviolet light irradiation. The effects of doped content, activation temperature, time, initial concentration of methanol and gas flow rate on the catalytic activity were investigated. The results showed that after doping a certain amount of CeO2 and ZrO2, crystallization process of TiO2 was restrained, particles of catalysts are smaller and more uniform. Doping ZrO2 not only significantly improved the catalytic activity, but also increased thermal stability. Doping H3PW12O40 alSO enhanced the catalytic activity. The catalytic activities of binary and ternary composite photocatalysts were significantly higher than un-doped TiO2. The dynamics law of photocatalytic reaction over the binary CeO2/TiO2 and ZrO2/TiO2 catalysts has been studied. The activation energy 15.627 and 15.631 kJ/mol and pre-exponential factors 0.5176 and 0.9899 s^-1 over each corresponding catalyst were obtained. This reaction accords to the first order dynamics law.展开更多
文摘便携式电子产品、电动汽车和储能领域的快速发展对电池能量密度的要求越来越高,正极材料是限制电池能量密度的主要因素。过渡金属氟磷酸盐(A2MPO4F,A=Li、Na,M=Mn、Fe、Co、Ni)是一类高比容量(~300 m A·h/g)和高能量密度(>1000 W·h/kg)的新型正极材料。主要介绍了A2MPO4F的结构、合成方法与改性方面的最新进展。讨论了A2MPO4F所面临的主要挑战,特别是实现两电子反应所面临的困难。展望了它们的应用前景。
基金the Hunan Provin-cial Natural Science Foundationthe Scientific Research Fund of Education Department and the Organic Chemistry Key Subject
文摘The binary composite photo-catalysts CeO2/ZiO2, ZrO2/ZiO2 and the ternary composite photo-catalysts H3PW12040-CeO2/TiO2, H3PW12O40-ZrO2/TiO2 were prepared by sol-gel method. The catalysts were characterized by thermogravimetric-differential thermal analysis （TG-DTA）, scanning electron microscopy （SEM） and X-ray diffraction （XRD）. The photocatalytic elimination of methanol was used as model reaction to evaluate the photocatalytic activity of the composite catalysts under ultraviolet light irradiation. The effects of doped content, activation temperature, time, initial concentration of methanol and gas flow rate on the catalytic activity were investigated. The results showed that after doping a certain amount of CeO2 and ZrO2, crystallization process of TiO2 was restrained, particles of catalysts are smaller and more uniform. Doping ZrO2 not only significantly improved the catalytic activity, but also increased thermal stability. Doping H3PW12O40 alSO enhanced the catalytic activity. The catalytic activities of binary and ternary composite photocatalysts were significantly higher than un-doped TiO2. The dynamics law of photocatalytic reaction over the binary CeO2/TiO2 and ZrO2/TiO2 catalysts has been studied. The activation energy 15.627 and 15.631 kJ/mol and pre-exponential factors 0.5176 and 0.9899 s^-1 over each corresponding catalyst were obtained. This reaction accords to the first order dynamics law.
