An increasingly important step in the design of three-way catalytic converters is having the ability to evaluate deactivation of potential catalyst formulations with accelerated testing. Most accelerated tests involve deactivating the catalyst by thermal (i.e., high temperature) and/or poisoning mechanisms using an engine/dynamometer. Efficient utilization of the engine/dynamometer tests involves optimizing the test conditions such that the largest amount of information can be gathered under the simplest and shortest test conditions. Optimization of the test, however, requires first the task of determining the mechanisms of catalyst deactivation during the test. Mechanisms of catalyst deactivation were studied for a (gamma-alumina) bead supported Pt/Rh three-way catalyst during the course of a high temperature accelerated test. High temperature aging experiments in the laboratory were coupled with the results of the accelerated test to gain in sight into the mechanisms causing the high temperature deactivation. Results of the laboratory aging experiments showed that loss of three-way conversion efficiency occurred readily under oxidizing conditions but not under neutral or reducing conditions. The loss of three-way conversion efficiency after exposure to high temperature oxidizing conditions could be regenerated by exposing the catalyst to high temperature reducing conditions. Oxidation of Rh was found to be the predominant deactivation mechanism in oxidizing conditions. Reduction of Rh oxide back to Rh metal explained the observed regeneration results. Regeneration of a catalyst exposed to the high temperature accelerated test also showed the mechanism of deactivation during the accelerated test was predominately one of oxidation of Rh.


    Access

    Check access

    Check availability in my library

    Order at Subito €


    Export, share and cite



    Title :

    High Temperature Deactivation of Three-Way Catalyst


    Additional title:

    Sae Technical Papers


    Contributors:
    Mann, G. S. (author) / Carol, L. A. (author) / Newman, N. E. (author)

    Conference:

    1989 SAE International Fall Fuels and Lubricants Meeting and Exhibition ; 1989



    Publication date :

    1989-09-01




    Type of media :

    Conference paper


    Type of material :

    Print


    Language :

    English




    High temperature deactivation of three-way catalyst

    Carol,L.A. / Newman,N.E. / Mann,G.S. et al. | Automotive engineering | 1989


    Three-way Catalyst Deactivation Associated With Oil-Derived Poisons

    Kubsh, J. / Deutsche Gesellschaft fur Materialkunde | British Library Conference Proceedings | 2002


    Thermal effect on three-way catalyst deactivation and improvement

    Ihara,K. / Ohkubo,K. / Niura,Y. et al. | Automotive engineering | 1987


    A Study on Three Way Conversion Catalyst Thermal Deactivation and improvement

    Funabiki, Masaki / Yamada, Teiji | SAE Technical Papers | 1988


    Hydrocarbon deactivation of hydrocarbon SCR catalyst

    Cheng,S.W. / Mulawa,P.A. / General Motors Res.and Dev.Center,US | Automotive engineering | 2009