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Surface Oxidation of Supported Ni Particles and Its Impact on the Catalytic Performance during Dynamically Operated Methanation of CO₂

Mutz, Benjamin 1,2; Gänzler, Andreas Martin 2; Nachtegaal, Maarten; Müller, Oliver; Frahm, Ronald; Kleist, Wolfgang 1,2; Grunwaldt, Jan-Dierk ORCID iD icon 1,2
1 Institut für Katalyseforschung und -technologie (IKFT), Karlsruher Institut für Technologie (KIT)
2 Institut für Technische Chemie und Polymerchemie (ITCP), Karlsruher Institut für Technologie (KIT)


The methanation of CO₂ within the power-to-gas concept was investigated under fluctuating reaction conditions to gather detailed insight into the structural dynamics of the catalyst. A 10 wt % Ni/Al2O3 catalyst with uniform 3.7 nm metal particles and a dispersion of 21% suitable to investigate structural changes also in a surface-sensitive way was prepared and characterized in detail. Operando quick-scanning X-ray absorption spectroscopy (XAS/QEXAFS) studies were performed to analyze the influence of 30 s and 300 s H₂ interruptions during the methanation of CO₂ in the presence of O₂ impurities (technical CO₂). These conditions represent the fluctuating supply of H2 from renewable energies for the decentralized methanation. Short-term H₂ interruptions led to oxidation of the most reactive low-coordinated metallic Ni sites, which could not be re-reduced fully during the subsequent methanation cycle and accordingly caused deactivation. Detailed evaluation of the extended X-ray absorption fine structure (EXAFS) spectra showed surface oxidation/reduction processes, whereas the core of the Ni particles remained reduced. The 300-s H₂ interruptions resulted in bulk oxidation already after the first cycle and a more pronounced deactivation. ... mehr

Verlagsausgabe §
DOI: 10.5445/IR/1000076025
Veröffentlicht am 27.10.2017
DOI: 10.3390/catal7090279
Zitationen: 58
Web of Science
Zitationen: 52
Zitationen: 59
Cover der Publikation
Zugehörige Institution(en) am KIT Institut für Katalyseforschung und -technologie (IKFT)
Institut für Technische Chemie und Polymerchemie (ITCP)
Publikationstyp Zeitschriftenaufsatz
Publikationsjahr 2017
Sprache Englisch
Identifikator ISSN: 2073-4344
KITopen-ID: 1000076025
HGF-Programm 37.03.01 (POF III, LK 01) Catalysts and Mechanisms
Erschienen in Catalysts
Verlag MDPI
Band 7
Heft 9
Seiten 279
Bemerkung zur Veröffentlichung This article belongs to the Special Issue Catalytic, Photocatalytic and Electrocatalytic Processes for the Valorisation of CO₂
Gefördert durch den KIT-Publikationsfonds
Vorab online veröffentlicht am 18.09.2017
Schlagwörter CO₂ methanation, dynamic reaction conditions, operando XAS, quick-EXAFS, surface oxidation-reduction, H₂ dropout
Nachgewiesen in Dimensions
Web of Science
Globale Ziele für nachhaltige Entwicklung Ziel 7 – Bezahlbare und saubere Energie
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