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


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-Al 2O 3, 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 CO 2 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 Rh 0, its relative content decreasing in the order Rh/CZ(100%)>Rh/ACZ(72%)>Rh/γ-Al 2O 3(55%). The catalytic activity followed the same order, demonstrating unambiguously that Rh 0 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-Al 2O 3 consistent with a bi-functional reaction mechanism whereby backspillover of labile lattice O 2− contributes to carbon oxidation, stabilization of Rh 0 and modification of its surface chemistry; the resulting O vacancies in the support providing centers for dissociative adsorption of CO 2. The lower apparent activation energy observed with CZ-containing samples suggests that CZ is a promising support component for use in low temperature DRM.

Publication DOI: https://doi.org/10.1016/j.apcatb.2018.10.048
Dataset DOI: https://doi.org/10.17036/researchdata.aston.ac.uk.00000391
Divisions: College of Engineering & Physical Sciences
College of Engineering & Physical Sciences > Energy and Bioproducts Research Institute (EBRI)
Additional Information: © 2018, Elsevier. Licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International http://creativecommons.org/licenses/by-nc-nd/4.0/. Funding: European Union and Greek national funds through the Operational Program "Competitiveness, Entrepreneurship and Innovation", under the call “RESEARCH-CREATE-INNOVATE” (project code: T1EΔK-00782), Royal Society and EPSRC (EP/M005186/2).
Uncontrolled Keywords: Active sites,CO activation,Dry reforming of methane,Oxygen ions spillover,Oxygen storage capacity,Resistance to carbon deposition,Rhodium nanoparticles,Support effects,Synthesis gas,Catalysis,Environmental Science(all),Process Chemistry and Technology
Publication ISSN: 1873-3883
Last Modified: 03 Jun 2024 07:35
Date Deposited: 29 Oct 2018 08:50
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Related URLs: https://linking ... 92633731831004X (Publisher URL)
http://www.scop ... tnerID=8YFLogxK (Scopus URL)
PURE Output Type: Article
Published Date: 2019-04-01
Published Online Date: 2018-10-28
Accepted Date: 2018-10-22
Authors: 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 (ORCID Profile 0000-0003-1334-127X)
Kyriakou, Georgios
Holgado, Juan Pedro
Lambert, Richard M.

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