Controllable synthesis of nearly monodisperse spherical aggregates of CeO2 nanocrystals and their catalytic activity for HCHO oxidation.
Controllable synthesis of nearly monodisperse spherical aggregates of CeO2 nanocrystals and their catalytic activity for HCHO oxidation.
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DOI：
10.1002/asia.201200432
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发表时间：
2012-10
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影响因子：
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通讯作者：
Qin Wang;Wenjing Jia;Baocang Liu;Wenzhi Zhao;Changyan Li;Jun Zhang;Gangran Xu
中科院分区：
文献类型：
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作者：
Qin Wang;Wenjing Jia;Baocang Liu;Wenzhi Zhao;Changyan Li;Jun Zhang;Gangran Xu
在这里，我们报道了一种简便的表面活性剂辅助溶剂热合成方法来制备近单分散的球形CeO(2)纳米晶。通过改变反应时间、乙醇与水的体积比(R)、PVP的摩尔比和Ce(NO3)(3)⋅6H(2)O的浓度等合成参数，可以很好地控制CeO2纳米晶的尺寸在10 0~5 0 0 nm范围内。提出了球形CeO(2)纳米晶生长的可能机制。得到了比表面积高达47m(2)g(-1)的CeO(2)纳米晶，并将其用作催化剂载体。通过在CeO(2)载体上负载Au-Pd纳米粒子(约3wt.%)，制备了对甲醛氧化具有高催化活性的Au-Pd/CeO(2)催化剂。在50℃的低温下，甲醛转化率为100%，在优先氧化等催化反应中具有潜在的应用前景。这些Au-Pd/CeO(2)催化剂还可用于室内甲醛净化和工业催化。这种简便的溶剂热法可以推广到其他金属氧化物纳米晶的制备，并为尺寸和形貌控制的合成提供指导。
Herein, we report a facile surfactant-assisted solvothermal synthetic method to prepare nearly monodisperse spherical CeO(2) nanocrystals. A good control of the size of CeO(2) nanocrystals in the range of 100-500 nm was achieved by simply varying the synthetic parameters such as reaction time, volume ratio of ethanol to water (R), molar ratio of PVP, and concentration of Ce(NO(3))(3)⋅6 H(2) O in solution. A possible mechanism for the growth of spherical CeO(2) nanocrystals is proposed. The obtained CeO(2) nanocrystals with a surface area of up to 47 m(2) g(-1) were then employed as a catalyst support. By loading Au-Pd nanoparticles (about 3 wt. %) onto the CeO(2) support, an Au-Pd/CeO(2) catalyst was prepared that exhibited high catalytic activity for HCHO oxidation. At the low temperature of 50 °C, the percentage of HCHO conversion was 100 %, suggesting potential applications in preferential oxidation and other catalytic reactions. These Au-Pd/CeO(2) catalysts may also find applications in indoor formaldehyde decontamination and industrial catalysis. The facile solvothermal method can be extended to the preparation of other metal oxide nanocrystals and provides guidance for size- and morphology-controlled synthesis.