Modeling of bimetallic particles Pt+Rh: Application to a model catalyst for conversion of automobile engine exhaust studied by extended X-ray absorption fine structure analysis (EXAFS)

Model catalyst of automotive catalytic exhaust device containing platinum a nd rhodium supported over alumina have been studied by EXAFS. The results p roved that there is a formation of an alloy between the two metals, but tha t a fraction of the rhodium remains oxidised. A modelisation software confi rms at least partially those results and led to a model of particle contain ing a pure platinum core covered by several layers of pure rhodium or or in which the two matal are present together.