Fabrication and Testing of Low-Temperature Catalytically Active Washcoat Materials for Next-Generation Vehicle Catalytic Converters

The vehicle catalytic converter consists of three main components: the ceramic honeycomb substrate, the washcoat materials, and the catalysts. A washcoat is a carrier for the catalytic materials and is used to disperse the materials over a high surface area. The current Al<sub>2</sub>O<sub>3</sub>/CeO<sub>2</sub>-based washcoat materials is limited to rather high temperatures (>600<sup>o</sup>C) for the required oxygen storage capacity (OSC), which adversely affect the fuel efficiency of the engine-exhaust system. During cold start conditions, the low OSC of washcoat materials is especially problematic and provides the primary impetus for the development of lower temperature catalytically active washcoat materials for next generation vehicle catalytic converters. This proposed study presents an alternative approach for next generation vehicle catalytic converters by coating current inserts (i.e. cordierite ceramic honeycomb; cordierite: 2Al<sub>2</sub>O<sub>3</sub>&amp;#61655;2SiO<sub>2</sub>&amp;#61655;5MgO) with high surface area low-temperature catalytically active CeO<sub>2</sub> and CeO<sub>2</sub>-based mixed oxides nanorods and nanotubes. Because of the superior low-temperature catalytic activity of CeO<sub>2</sub> and CeO<sub>2</sub>-based mixed oxides nanorods and nanotubes, platinum group metal (PGM, Pt, Pd, Rh) can be deposited directly on the nanorods/nanocubes by impregnation techniques increasing the surface area that will be accessible to exhaust gases, thus resulting in increase of exhaust gas conversion efficiency and the decrease of the overall amount of the precious metal required. Also due to the small size and high porosity of the CeO<sub>2</sub> and CeO<sub>2</sub>-based mixed oxides nanorods and nanotubes, the presence of nanoscale CeO<sub>2</sub>-based washcoat materials has a negligible effect on the exhaust back pressure, which incurs a decrease of power output that must be compensated by increasing fuel consumption. In this proposal, specifically the authors will tackle the following objectives: 1) prepare high surface-area CeO<sub>2</sub> and CeO<sub>2</sub>-based mixed oxides nanorods and nanotubes washcoat materials using a solution-based hydrothermal method;  2) load washcoat materials onto commercial cordierite ceramic honeycomb by three different methods: spray method; impregnation method; in situ hydrothermal impregnation method, and investigate the thermal and chemical compatibility of the washcoat materials and ceramic honeycombs; 3) and test the low-temperature activity of CO conversion and thermal stability of new washcoat materials on commercial ceramic honeycombs.

Language

  • English

Project

  • Status: Completed
  • Funding: $100000.00
  • Contract Numbers:

    DTRT06-G0041

  • Sponsor Organizations:

    Research and Innovative Technology Administration

    University Transportation Centers Program
    1200 New Jersey Avenue
    Washington, DC  United States  20590
  • Performing Organizations:

    Youngstown State University Center for Transportation and Materials Engineering

    Youngstown State University
    One University Plaza
    Youngstown, OH  United States  44555
  • Principal Investigators:

    Esenwein, Joann

    Wang, Ruigang

  • Start Date: 20130201
  • Expected Completion Date: 0
  • Actual Completion Date: 20131231
  • Source Data: RiP Project 33748

Subject/Index Terms

Filing Info

  • Accession Number: 01503575
  • Record Type: Research project
  • Source Agency: Youngstown State University Center for Transportation and Materials Engineering
  • Contract Numbers: DTRT06-G0041
  • Files: UTC, RiP
  • Created Date: Jan 14 2014 1:00AM