KIT | KIT-Bibliothek | Impressum | Datenschutz

Effects of hydrothermal aging on co and no oxidation activity over monometallic and bimetallic pt‐pd catalysts

Schütz, Jochen; Störmer, Heike; Lott, Patrick; Deutschmann, Olaf

Abstract:
By combining scanning transmission electron microscopy, CO chemisorption, and energy dispersive X-ray spectroscopy with CO and NO oxidation light-off measurements we investigated deactivation phenomena of Pt/Al$_{2}$O$_{3}$, Pd/Al$_{2}$O$_{3}$, and Pt-Pd/Al$_{2}$O$_{3}$ model diesel oxidation catalysts during stepwise hydrothermal aging. Aging induces significant particle sintering that results in a decline of the catalytic activity for all catalyst formulations. While the initial aging step caused the most pronounced deactivation and sintering due to Ostwald ripening, the deactivation rates decline during further aging and the catalyst stabilizes at a low level of activity. Most importantly, we observed pronounced morphological changes for the bimetallic catalyst sample: hydrothermal aging at 750 °C causes a stepwise transformation of the Pt-Pd alloy via core-shell structures into inhomogeneous agglomerates of palladium and platinum. Our study shines a light on the aging behavior of noble metal catalysts under industrially relevant conditions and particularly underscores the highly complex transformation of bimetallic Pt-Pd diesel oxidation catalysts during hydrothermal treatment

Open Access Logo


Verlagsausgabe §
DOI: 10.5445/IR/1000130506
Veröffentlicht am 19.03.2021
Cover der Publikation
Zugehörige Institution(en) am KIT Institut für Technische Chemie und Polymerchemie (ITCP)
Laboratorium für Elektronenmikroskopie (LEM)
Publikationstyp Zeitschriftenaufsatz
Publikationsjahr 2021
Sprache Englisch
Identifikator ISSN: 2073-4344
KITopen-ID: 1000130506
Erschienen in Catalysts
Verlag MDPI
Band 11
Heft 3
Seiten 1-18
Nachgewiesen in Scopus
KIT – Die Forschungsuniversität in der Helmholtz-Gemeinschaft
KITopen Landing Page