层状过渡金属氧化物由于其较高的理论比容量和较低的经济成本,被视为一种具有良好应用前景的钠离子电池正极材料。采用溶胶-凝胶法和热处理的方式,制备Ca/Cu共掺杂的铁锰基层状氧化物(O3-Na_(0.9)Ca_(0.05)Fe_(0.45)Mn_(0.45)Cu_(0.1O)_...层状过渡金属氧化物由于其较高的理论比容量和较低的经济成本,被视为一种具有良好应用前景的钠离子电池正极材料。采用溶胶-凝胶法和热处理的方式,制备Ca/Cu共掺杂的铁锰基层状氧化物(O3-Na_(0.9)Ca_(0.05)Fe_(0.45)Mn_(0.45)Cu_(0.1O)_(2))。采用X射线衍射仪(XRD)、场发射扫描电子显微镜(SEM)、透射电子显微镜(TEM)、X射线光电子能谱(XPS)等对该O3型铁锰基层状氧化物正极材料进行表征分析。结果表明,在32 mA/g电流密度下该材料具有205.2 m A·h/g的高比容量,循环50圈之后仍具有67.64%的容量保持率,在160 m A/g下循环100圈后依然具有81.4 m A·h/g的放电比容量。由于Ca的掺入,引起Na^(+)空位的增加,并且Cu的掺入提高了Mn的价态,从而提高了Na^(+)的扩散速率,抑制了Mn3+的Jahn-Teller效应,缓解了晶格应力,有效提高了材料的结构稳定性和电化学性能。展开更多
Zr0.5Ti0.5O2(ZT) and Zr0.25Ti0.25Al0.5O2(ZTA) mixed oxides were prepared by co-precipitation method and characterized by low temperature adsorption-desorption,XRD and NH3-TPD. The activity of Pt/Zr0.5Ti0.5O2 and Pt/ Z...Zr0.5Ti0.5O2(ZT) and Zr0.25Ti0.25Al0.5O2(ZTA) mixed oxides were prepared by co-precipitation method and characterized by low temperature adsorption-desorption,XRD and NH3-TPD. The activity of Pt/Zr0.5Ti0.5O2 and Pt/ Zr0.5Ti0.5Al0.5O2 catalysts was evaluated using the simulated gases. The results show that ZTA samples exhibit higher specific surface area,larger pore volume and proper surface acidic amount and acidity in comparison with ZT. The results of the catalytic test indicate that Pt/ZT and Pt/ZTA catalysts exhibit excellent low-temperature catalytic activity and lower light-off temperatures of hydrocarbon,carbon monoxide and nitrogen oxides,especially better conversion for nitrogen oxides (NOx). The addition of Al2O3 into ZT enhanced the anti-aging property of Pt/ ZTA catalysts due to the excellent textural,structural,surface acidity and thermal stability.展开更多
文摘层状过渡金属氧化物由于其较高的理论比容量和较低的经济成本,被视为一种具有良好应用前景的钠离子电池正极材料。采用溶胶-凝胶法和热处理的方式,制备Ca/Cu共掺杂的铁锰基层状氧化物(O3-Na_(0.9)Ca_(0.05)Fe_(0.45)Mn_(0.45)Cu_(0.1O)_(2))。采用X射线衍射仪(XRD)、场发射扫描电子显微镜(SEM)、透射电子显微镜(TEM)、X射线光电子能谱(XPS)等对该O3型铁锰基层状氧化物正极材料进行表征分析。结果表明,在32 mA/g电流密度下该材料具有205.2 m A·h/g的高比容量,循环50圈之后仍具有67.64%的容量保持率,在160 m A/g下循环100圈后依然具有81.4 m A·h/g的放电比容量。由于Ca的掺入,引起Na^(+)空位的增加,并且Cu的掺入提高了Mn的价态,从而提高了Na^(+)的扩散速率,抑制了Mn3+的Jahn-Teller效应,缓解了晶格应力,有效提高了材料的结构稳定性和电化学性能。
文摘Zr0.5Ti0.5O2(ZT) and Zr0.25Ti0.25Al0.5O2(ZTA) mixed oxides were prepared by co-precipitation method and characterized by low temperature adsorption-desorption,XRD and NH3-TPD. The activity of Pt/Zr0.5Ti0.5O2 and Pt/ Zr0.5Ti0.5Al0.5O2 catalysts was evaluated using the simulated gases. The results show that ZTA samples exhibit higher specific surface area,larger pore volume and proper surface acidic amount and acidity in comparison with ZT. The results of the catalytic test indicate that Pt/ZT and Pt/ZTA catalysts exhibit excellent low-temperature catalytic activity and lower light-off temperatures of hydrocarbon,carbon monoxide and nitrogen oxides,especially better conversion for nitrogen oxides (NOx). The addition of Al2O3 into ZT enhanced the anti-aging property of Pt/ ZTA catalysts due to the excellent textural,structural,surface acidity and thermal stability.
