Operando XRD/PDF study of Pt and Pd three-way catalyst deactivation under realistic conditions

Atomically dispersed Pd/CeO2 and Pt/CeO2 are promising three-way catalysts since they reach full conversion of harmful gases such as CO and NOx at much lower temperatures than the current generation of commercial catalysts. One of their main drawbacks is their low stability at the high temperatures that can be reached inside a catalytic converter. Our objective is the comprehensive investigation of structural changes occurring during treatment of such catalysts under realistic three-way catalysis conditions.This involves high temperatures (>900°C), an artificial exhaust gas mixture and switches between oxidizing and reducing gas atmospheres. Using operando XRD and PDF, we plan to investigate the formation of metal and metal oxide phases as a function of temperature and redox conditions, observe the sintering kinetics of ceria and track the formation of oxygen vacancies in ceria in different gas atmospheres.