Details

Autor(en) / Beteiligte

• Yentekakis, Ioannis V.
• Goula, Grammatiki
• Hatzisymeon, Maria
• Betsi-Argyropoulou, Ioanna
• Botzolaki, Georgia
• Kousi, Kalliopi
• Kondarides, Dimitris I.
• Taylor, Martin J.
• Parlett, Christopher M.A.
• Osatiashtiani, Amin
• Kyriakou, Georgios
• Holgado, Juan Pedro
• Lambert, Richard M.

Titel

Effect of support oxygen storage capacity on the catalytic performance of Rh nanoparticles for CO2 reforming of methane

Ist Teil von

• Applied catalysis. B, Environmental, 2019-04, Vol.243, p.490-501

Ort / Verlag

Elsevier B.V

Erscheinungsjahr

2019

Link zum Volltext

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• [Display omitted] •High OSCs’ oxide supports promote CO-enriched syngas production of Rh-catalysed DRM.•Low carbon deposition was revealed, increasing in the order Rh/CZ < Rh/ACZ < Rh/γ-Al2O3.•O2− back-spillover from CZ to Rh particles determines Rh state and its DRM activity.•100% Rh0 active phase on Rh/CZ and only 55% Rh/Al2O3 were found after DRM.•Reduced apparent activation energy for Rh/CZ indicates a promising LT-DRM material. The effects of the metal oxide support on the activity, selectivity, resistance to carbon deposition and high temperature oxidative aging on the Rh-catalyzed dry reforming of methane (DRM) were investigated. Three Rh catalysts supported on oxides characterized by very different oxygen storage capacities and labilities (γ-Al2O3, alumina-ceria-zirconia (ACZ) and ceria-zirconia (CZ)) were studied in the temperature interval 400–750 °C under both integral and differential reaction conditions. ACZ and CZ promoted CO2 conversion, yielding CO-enriched synthesis gas. Detailed characterization of these materials, including state of the art XPS measurements obtained via sample transfer between reaction cell and spectrometer chamber, provided clear insight into the factors that determine catalytic performance. The principal Rh species detected by post reaction XPS was Rh0, its relative content decreasing in the order Rh/CZ(100%)>Rh/ACZ(72%)>Rh/γ-Al2O3(55%). The catalytic activity followed the same order, demonstrating unambiguously that Rh0 is indeed the key active site. Moreover, the presence of CZ in the support served to maintain Rh in the metallic state and minimize carbon deposition under reaction conditions. Carbon deposition, low in all cases, increased in the order Rh/CZ < Rh/ACZ < Rh/γ-Al2O3 consistent with a bi-functional reaction mechanism whereby backspillover of labile lattice O2− contributes to carbon oxidation, stabilization of Rh0 and modification of its surface chemistry; the resulting O vacancies in the support providing centers for dissociative adsorption of CO2. The lower apparent activation energy observed with CZ-containing samples suggests that CZ is a promising support component for use in low temperature DRM.