title: Support Morphology-Dependent Catalytic Activity of Pd/CeO₂ for Formaldehyde Oxidation.
abstract: 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 10,000 h(-1) 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 (1-2 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.
authors.affiliation: School of Chemistry and Chemical Engineering, University of Chinese Academy of Sciences, Beijing 100049, P.R. China.
authors.forename: Hongyi
authors.initials: H
authors.lastname: Tan
authors.affiliation: School of Chemistry and Chemical Engineering, University of Chinese Academy of Sciences, Beijing 100049, P.R. China.
authors.forename: Jin
authors.initials: J
authors.lastname: Wang
authors.affiliation: School of Chemistry and Chemical Engineering, University of Chinese Academy of Sciences, Beijing 100049, P.R. China.
authors.forename: Shuzhen
authors.initials: S
authors.lastname: Yu
authors.affiliation: School of Chemistry and Chemical Engineering, University of Chinese Academy of Sciences, Beijing 100049, P.R. China.
authors.forename: Kebin
authors.initials: K
authors.lastname: Zhou
mesh_terms: D016902:Air Pollution, Indoor; D002245:Carbon Dioxide / Q000737:chemistry; D002384:Catalysis; D002563:Cerium / Q000737:chemistry*; D005557:Formaldehyde / Q000737:chemistry*; D046529:Microscopy, Electron, Transmission; D053758:Nanoparticles / Q000737:chemistry*; D043942:Nanotubes / Q000737:chemistry; D010084:Oxidation-Reduction; D010100:Oxygen / Q000737:chemistry; D010165:Palladium / Q000737:chemistry*; D014961:X-Ray Diffraction
chemical_list: D002245:Carbon Dioxide; D005557:Formaldehyde; D002563:Cerium; D010165:Palladium; C030583:ceric oxide; D010100:Oxygen