Support Morphology-Dependent Catalytic Activity of Pd/CeO2 for Formaldehyde Oxidation

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• 作者：Hongyi Tan ; Jin Wang ; Shuzhen Yu ; Kebin Zhou
• 刊名：Environmental Science & Technology
• 出版年：2015
• 出版时间：July 21, 2015
• 年：2015
• 卷：49
• 期：14
• 页码：8675-8682
• 全文大小：482K
• ISSN：1520-5851

文摘

To eliminate indoor formaldehyde (HCHO) pollution, Pd/CeO₂ catalysts with different morphologies of ceria support were employed. The palladium nanoparticles loaded on {100}-faceted CeO₂ nanocubes exhibited much higher activity than those loaded on {111}-faceted ceria nanooctahedrons and nanorods (enclosed by {100} and {111} facets). The HCHO could be fully converted into CO₂ over the Pd/CeO₂ nanocubes at a GHSV of 10鈥?00 h^鈥? and a HCHO inlet concentration of 600 ppm at ambient temperature. The prepared catalysts were characterized by a series of techniques. The HRTEM, ICP-MS and XRD results confirmed the exposed facets of the ceria and the sizes (1鈥? nm) of the palladium nanoparticles with loading amounts close to 1%. According to the Pd 3d XPS and H₂-TPR results, the status of the Pd-species was dependent on the morphologies of the supports. The {100} facets of ceria could maintain the metallic Pd species rather than the {111} facets, which promoted HCHO catalytic combustion. The Raman and O 1s XPS results revealed that the nanorods with more defect sites and oxygen vacancies were responsible for the easy oxidation of the Pd-species and low catalytic activity.