Characterization of the Automotive Exhaust Gas Aftertreatment Catalysts with Flow Chemisorption Methods
Доклады на конференциях
Applications of the chemisorption methods (pulse chemisorption, Temperature-programmed desorption (TPD), reduction (TPR) and oxidation (TPO)) to characterization of the thermal aging of the automotive exhaust catalysts, was described. Pulse chemisorption and TPR were applied to study deactivation of the LNT catalyst. Relatively safe rich operation temperature for LNT was found to be ca. 800°C. Above this temperature, rapid irreversible deactivation due to PGM and support sintering were taking place. For evaluated NH3 SCR catalyst, ammonia TPD study helped to determine not-to-exceed temperature of ca. 900°C. Above this temperature, there is a high probability that zeolite will undergo destruction, so all NH3 SCR reaction related properties will be irreversibly lost.
For the sample of the in-field failed three-way catalyst, temperature of the exposure was deducted based on the characterization of the catalyst with CO pulse chemisorption and TPR.