The Mn-doped Ce02 nanopowders with high catalysis activity were successfully fabricated through a simple hydrolyzed-oxidized approach. Firstly, the alloy Ce37Mnl 8C45 was prepared in vacuum induction melting furnace. ...The Mn-doped Ce02 nanopowders with high catalysis activity were successfully fabricated through a simple hydrolyzed-oxidized approach. Firstly, the alloy Ce37Mnl 8C45 was prepared in vacuum induction melting furnace. Subsequently, Mn-doped CeO2 nanopowders with 142 m2/g of specific surface area were obtained through a simple hydrolyzed-oxidized procedure of the alloy Those nanopowders were heat treated at different temperatures. The obtained materials were characterized by X-ray diffraction （XRD）, transmission electron microscopy （TEM）, high-resolution transmission electron microscopy （HRTEM） and energy dispersive spectroscopy （EDS）. And the catalytic activity on vinyl chloride （VC） emission combustion was investigated. The results showed that those nanopowders after hydrolyzed-oxidized from Ce37Mn18C45 mainly consisted of CeO2 and Mn304. Manganese element increased the thermal stability of CeO2 nanopowders. The Mn-doped CeO2 nanopowders had three morphologies. Small particles were Mn-doped CeO2, square particles were Mn304 and the rods were Mn304 and Mn203. The Mn-doped CeO2 nanopowders had good vinyl chloride （VC） emission catalytic performance.展开更多
气氛环境下原位研究催化剂的烧结行为,能够为理解催化剂在预处理以及反应条件下的烧结机理和高稳定催化剂的设计提供重要的实验依据。本文以Au/CeO_(2)模型纳米催化剂为研究对象,利用环境透射电子显微镜原位观察其在O_(2)与CO气氛下的...气氛环境下原位研究催化剂的烧结行为,能够为理解催化剂在预处理以及反应条件下的烧结机理和高稳定催化剂的设计提供重要的实验依据。本文以Au/CeO_(2)模型纳米催化剂为研究对象,利用环境透射电子显微镜原位观察其在O_(2)与CO气氛下的高温动态烧结过程。实验发现,负载在CeO_(2)上的Au纳米颗粒在O_(2)与CO气氛环境中表现出不同的烧结行为,其在O_(2)气氛下具有较高的烧结速度,同时存在颗粒迁移与聚集长大(particle migration and coalescence,PMC)和奥斯特瓦尔德熟化(Ostwald ripening,OR)两种烧结过程;在CO气氛下烧结速度较慢,烧结过程以OR为主。对比不同气氛环境下烧结后催化剂的表面结构可知,CO增加了CeO_(2)表面台阶的数量以及表面氧空位浓度,增强了载体对Au颗粒的锚定作用,从而提升Au/CeO_(2)催化剂的稳定性。展开更多
基金Project supported by Shanghai Leading Academic Discipline Project (S30107)
文摘The Mn-doped Ce02 nanopowders with high catalysis activity were successfully fabricated through a simple hydrolyzed-oxidized approach. Firstly, the alloy Ce37Mnl 8C45 was prepared in vacuum induction melting furnace. Subsequently, Mn-doped CeO2 nanopowders with 142 m2/g of specific surface area were obtained through a simple hydrolyzed-oxidized procedure of the alloy Those nanopowders were heat treated at different temperatures. The obtained materials were characterized by X-ray diffraction （XRD）, transmission electron microscopy （TEM）, high-resolution transmission electron microscopy （HRTEM） and energy dispersive spectroscopy （EDS）. And the catalytic activity on vinyl chloride （VC） emission combustion was investigated. The results showed that those nanopowders after hydrolyzed-oxidized from Ce37Mn18C45 mainly consisted of CeO2 and Mn304. Manganese element increased the thermal stability of CeO2 nanopowders. The Mn-doped CeO2 nanopowders had three morphologies. Small particles were Mn-doped CeO2, square particles were Mn304 and the rods were Mn304 and Mn203. The Mn-doped CeO2 nanopowders had good vinyl chloride （VC） emission catalytic performance.
文摘气氛环境下原位研究催化剂的烧结行为,能够为理解催化剂在预处理以及反应条件下的烧结机理和高稳定催化剂的设计提供重要的实验依据。本文以Au/CeO_(2)模型纳米催化剂为研究对象,利用环境透射电子显微镜原位观察其在O_(2)与CO气氛下的高温动态烧结过程。实验发现,负载在CeO_(2)上的Au纳米颗粒在O_(2)与CO气氛环境中表现出不同的烧结行为,其在O_(2)气氛下具有较高的烧结速度,同时存在颗粒迁移与聚集长大(particle migration and coalescence,PMC)和奥斯特瓦尔德熟化(Ostwald ripening,OR)两种烧结过程;在CO气氛下烧结速度较慢,烧结过程以OR为主。对比不同气氛环境下烧结后催化剂的表面结构可知,CO增加了CeO_(2)表面台阶的数量以及表面氧空位浓度,增强了载体对Au颗粒的锚定作用,从而提升Au/CeO_(2)催化剂的稳定性。
