Die CO‐Oxidation als Modellreaktion für heterogene Prozesse

Abstract

Die CO‐Oxidation, obwohl eine scheinbar einfache chemische Reaktion, dient als ein Modell, welches die Vielfalt und Attraktivität der heterogenen Katalyse offenbart. Das Fritz‐Haber‐Institut ist ein Ort, an dem ein multidisziplinärer Forschungsansatz zum Studium einer solchen heterogenen Reaktion innerhalb eines Instituts entwickelt und umgesetzt werden kann. Dabei ist die Forschung am Institut primär durch Neugier getrieben, was sich auch in den fünf Abschnitten dieses Aufsatzes widerspiegelt. Wir nutzen dabei mikroskopische Konzepte, um die Wechselwirkung einfacher Moleküle mit wohldefinierten Materialien wie Clustern in der Gasphase oder festen Oberflächen zu untersuchen. Dieser Ansatz erfordert nicht selten die Entwicklung von neuen Methoden, Werkzeugen und Materialien zur Verifizierung dieser Konzepte, und dies ermöglicht eine methodologisch solide, breit aufgestellte Herangehensweise als ein Markenzeichen des Instituts.

Doping Effects in Cluster‐Mediated Bond Activation

“…Arguably,t he metal-mediated CO!CO 2 conversion is one of the most often studied systems,both at surfaces [39] and in the gas phase. [40] In recent years,the focus of interest shifted from the investigation of homonuclear to "doped" clusters,as it turned out that even seemingly simple phenomena, such as adsorption energies,d issociative versus physical adsorption, and cluster reorganization or cluster fragmentation upon landing of CO,c rucially depend on the composition of the heteronuclear clusters.…”

CO oxidation as a test reaction for strong metal–support interaction in nanostructured Pd/FeO powder catalysts

“…These UHV-studies have been recently complemented by investigations in our group on more realistic catalysts [10,11]. Post-synthesis treatment of co-precipitated Pd/iron oxide catalysts was found to be crucial for the induction of phase-transition in the supporting iron oxide (from Fe 2 O 3 to Fe 3 O 4 polymorph).…”

Strong metal-support interaction and alloying in Pd/ZnO catalysts for CO oxidation

“…The same observations were made by Johnson et al [28] who investigated CO-oxidation and CO-adsorption on ␣-and ␤-PdZn and observed 5-10 times higher initial rates for the reaction, compared to pure Pd, however observing also deactivation upon time by zinc oxidation. CO-oxidation in general was intensively studied and discussed as a suitable model reaction for various heterogeneous, catalytic processes [29]. In the present work we study the role of SMSI in the Pd/ZnO system, by applying a similar, methodological approach, recently applied on the Pd/Fe 2 O 3 system [30]: the change of activity for CO-oxidation during SMSI/alloy formation as well as the reversibility by reoxidation will be investigated and compared to the changing structural and electronic characteristics.…”