Pt supported on octahedral Fe3O4 microcrystals as a catalyst for removal of formaldehyde under ambient conditions

Several catalysts comprising Pt supported on octahedral Fe3O4 (Pt/Fe3O4) were prepared by a facile method involving co-precipitation followed by thermal treatment at different temperatures. A variety of characterization results revealed that this preparation process afforded highly crystalline octahedral Fe3O4 with a uniform distribution of Pt nanoparticles on its surface. The thermal-treatment temperature significantly influenced the redox properties of the Pt/Fe3O4 catalysts. All the Pt/Fe3O4 catalysts were found to be catalytically active and stable for the oxidation of low-concentration formaldehyde (HCHO) with oxygen. The catalyst prepared by thermal treatment at 80 degrees C (labelled Pt/Fe3O4-80) exhibited the highest catalytic activity, efficiently converting HCHO to CO2 and H2O under ambient temperature and moisture conditions. The excellent performance of Pt/Fe3O4-80 was mainly attributed to beneficial interactions between the Pt and Fe species that result in the formation a higher density of active interface sites (e.g., Pt-O-FeOx, and Pt-OH-FeOx). The introduction of water vapor improves the catalytic activity of the Pt/Fe3O4 catalysts as it participates in a water-assisted dissociation process. (C) 2018, Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.