Details

Autor(en) / Beteiligte

• Muravev, Valery
• Simons, Jérôme F. M.
• Parastaev, Alexander
• Verheijen, Marcel A.
• Struijs, Job J. C.
• Kosinov, Nikolay
• Hensen, Emiel J. M.

Titel

Operando Spectroscopy Unveils the Catalytic Role of Different Palladium Oxidation States in CO Oxidation on Pd/CeO2 Catalysts

Ist Teil von

• Angewandte Chemie International Edition, 2022-06, Vol.61 (23), p.e202200434-n/a

Auflage

International ed. in English

Ort / Verlag

Weinheim: Wiley Subscription Services, Inc

Erscheinungsjahr

2022

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Aiming at knowledge‐driven design of novel metal–ceria catalysts for automotive exhaust abatement, current efforts mostly pertain to the synthesis and understanding of well‐defined systems. In contrast, technical catalysts are often heterogeneous in their metal speciation. Here, we unveiled rich structural dynamics of a conventional impregnated Pd/CeO2 catalyst during CO oxidation. In situ X‐ray photoelectron spectroscopy and operando X‐ray absorption spectroscopy revealed the presence of metallic and oxidic Pd states during the reaction. Using transient operando infrared spectroscopy, we probed the nature and reactivity of the surface intermediates involved in CO oxidation. We found that while low‐temperature activity is associated with sub‐oxidized and interfacial Pd sites, the reaction at elevated temperatures involves metallic Pd. These results highlight the utility of the multi‐technique operando approach for establishing structure–activity relationships of technical catalysts. Establishing structure–activity relationships for practical catalysts requires a multi‐technique operando approach. Using advanced spectroscopic tools and kinetic methods the catalytic role of different Pd oxidation states in CO oxidation was unveiled for Pd/CeO2 catalysts. Single‐atom Pd–oxo species and Pd−O−Ce interface are responsible for low‐temperature activity, whereas metallic Pd sites significantly contribute only at elevated temperature.