When the three-way conversion (TWC) catalysts were aged on representative 1977 unleaded commercial fuel, they had higher conversion efficiencies and improved durability than catalysts aged on modified 1975 FTP specification fuel containing approximately 0.025 g/gal Pb and low levels of phosphorus. As the rhodium content was increased in a series of platinum-rhodium TWC catalysts, the maximum conversion efficiency and durability increased, and the mine recovery ratio of Pt/Rh was found to be most susceptible to lead poisoning. However, good NOx efficiencies can be obtained from mine recovery ratio Pt/Rh TWC catalysts after 25,000 miles of engine aging. It is shown that improvements in catalyst formulations containing mine recovery ratio Pt/Rh resulted in higher conversion efficiencies. Monolithic TWC catalysts require approximately the same total precious metal as current oxidation catalysts. Particulate TWC catalysts show beneficial effects in increasing the precious metal loading above 15 grams/cubic foot.


    Access

    Check access

    Check availability in my library

    Order at Subito €


    Export, share and cite



    Title :

    Three-Way Conversion Catalysts Part of the New Emission Control System


    Additional title:

    Sae Technical Papers


    Contributors:

    Conference:

    1977 International Automotive Engineering Congress and Exposition ; 1977



    Publication date :

    1977-02-01




    Type of media :

    Conference paper


    Type of material :

    Print


    Language :

    English




    Three-Way Conversion Catalysts Part of the New Emission Control System

    Mooney,J.J. / Thompson,C.E. / Dettling,J.C. et al. | Automotive engineering | 1977


    Durability of palladium only three-way automotive emission control catalysts

    Summers,J.C. / White,J.J. / Williamson,W.B. et al. | Automotive engineering | 1989


    Noble metal usage reduction strategies for three-way emission control catalysts

    Summers,J.C. / Hiera,J.P. / Williamson,W.B. | Automotive engineering | 1991


    Noble Metal Usage Reduction Strategies for Three-Way Emission Control Catalysts

    Summers, J.C. / Hiera, J.P. / Williamson, W.B. | SAE Technical Papers | 1991