Systematic operando XAS studies of Pd/Al2O3 and Pd/CeO2-ZrO2 three-way catalysts

The study aims at understanding mechanistic details of three-way catalysts (TWC) by exploring the struc-ture of Pd species in Pd/Al2O3 and Pd/CeO2-ZrO2 catalysts during systematic variation of reaction atmos-phere, from simplified to realistic gas mixtures. The operando investigations of Pd K edge will be com-plementary to those conducted in our previous HERFD-XANES experiments at ID26 on Pd L3 edge (pro-posal MA-4916), and will contribute to a holistic comprehension of TWC functionality. In short, we will focus on: (1) identification of inhibition/boosting phenomena by operando monitoring the evolution in Pd oxidation state during interaction with CO, C3H6 and NO and their combinations, and (2) revealing the impact of catalyst support and reaction mixture on noble metal sintering and redispersion.