Hydrothermal Synthesis and Shape-Reactivity Correlation Study of Automotive Three-Way Nanocatalysts

The widely employed cerium based oxide three-way catalysts drastically reduce many of the critical pollutants (e.g., CO, NOx, and hydrocarbons) in automobile traffic. The nearly unsurpassed performance of the cerium oxide redox system is, however, limited to rather high temperatures (>600oC), which adversely effect the fuel efficiency of the engine-exhaust system. During cold start conditions, this is especially problematic and provides the primary impetus for the development of lower temperature catalysts. Surfaces play a crucial role for heterogeneous catalytic applications involving rare-earth oxides as the active species. The control of the crystal morphology presents itself as one of the major obstacles towards the development of more low-temperature active CeO2 based catalysts. In a recent pilot study, the project was able to synthesize well-dispersed single-crystalline CeO2 nanocubes, nanocuboids and nanorods with more reactive surfaces such as {110}, {100}, {211} etc., using a facile hydrothermal method. In this proposal, the project proposes to synthesize a series of CeO2 and cerium-based mixed oxide nanopowders with controlled particle size and morphology using hydrothermal method, and carry out a detailed study on the correlation between particle shape, exposed crystal faces and overall catalytic performance. To measure the overall properties of the materials, some commonly used techniques will be employed including: (1) X-ray Diffraction (XRD); (2) Surface Area Measurement (BET); (3) Thermogravimetric; (4) Analysis (TGA) of Redox Processes; and (5) Temperature Programmed Reduction and Oxidation (TPR and TPO). Powder X-ray diffraction will be performed to determine the overall crystallinity and structure of the materials. The surface areas will be measured using a Micromeritics Gemini Surface Area Analyser. TGA reduction and TPR will be performed with TA Q50 and Micromeritics AutoChemTM II 2920 instruments to measure the overall reducibility and catalytic activity of the materials, respectively. Transmission electron microscopy (TEM) will be used to determine the particle morphology and size, and nanoscale (or atomic level) structure and composition of individual nanoparticles.


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Filing Info

  • Accession Number: 01514358
  • Record Type: Research project
  • Source Agency: Youngstown State University Center for Transportation and Materials Engineering
  • Contract Numbers: DTRT06-G-0041
  • Files: UTC, RiP
  • Created Date: Feb 15 2014 1:00AM