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Verlagsausgabe
DOI: 10.5445/IR/1000076025#verlagsausgabe

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

Mutz, Benjamin; Gänzler, Andreas Martin; Nachtegaal, Maarten; Müller, Oliver; Frahm, Ronald; Kleist, Wolfgang; Grunwaldt, Jan-Dierk

Abstract:
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 inter ... mehr


Zugehörige Institution(en) am KIT Institut für Katalyseforschung und -Technologie (IKFT)
Institut für Technische Chemie und Polymerchemie (ITCP)
Publikationstyp Zeitschriftenaufsatz
Jahr 2017
Sprache Englisch
Identifikator ISSN: 2073-4344
URN: urn:nbn:de:swb:90-760258
KITopen ID: 1000076025
HGF-Programm 37.03.01; LK 01
Erschienen in Catalysts
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
Schlagworte CO₂ methanation, dynamic reaction conditions, operando XAS, quick-EXAFS, surface oxidation-reduction, H₂ dropout
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