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

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.

Abstract

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.

Citation

Yentekakis, I. V., Goula, G., Hatzisymeon, M., Betsi-Argyropoulou, I., Botzolaki, G., Kousi, K., Kondarides, D. I., Taylor, M. J., Parlett, C. M., Osatiashtiani, A., Kyriakou, G., Holgado, J. P., & Lambert, R. M. (2019). Effect of support oxygen storage capacity on the catalytic performance of Rh nanoparticles for CO2 reforming of methane. Applied catalysis. B, Environmental, 243, 490-501. https://doi.org/10.1016/j.apcatb.2018.10.048

• Journal Article Type: Article
• Acceptance Date: Oct 22, 2018
• Online Publication Date: Oct 28, 2018
• Publication Date: Apr 1, 2019
• Deposit Date: Dec 5, 2018
• Journal: Applied Catalysis B: Environmental
• Print ISSN: 0926-3373
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 243
• Pages: 490-501
• DOI: https://doi.org/10.1016/j.apcatb.2018.10.048
• Keywords: Dry reforming of methane; Active sites; Synthesis gas; Rhodium nanoparticles; Support effects; CO2 activation; Oxygen storage capacity; Resistance to carbon deposition; Oxygen ions spillover
• Public URL: https://hull-repository.worktribe.com/output/1172624
• Publisher URL: https://www.sciencedirect.com/science/article/pii/S092633731831004X?via%3Dihub
• Related Public URLs: https://research.aston.ac.uk/portal/en/researchoutput/effect-of-support-oxygen-storage-capacity-on-the-catalytic-performance-of-rh-nanoparticles-for-co2-reforming-of-methane(fbbdb6c7-8225-4119-93cd-79ba7267642b).html
• Additional Information: This article is maintained by: Elsevier; Article Title: Effect of support oxygen storage capacity on the catalytic performance of Rh nanoparticles for CO2 reforming of methane; Journal Title: Applied Catalysis B: Environmental; CrossRef DOI link to publisher maintained version: https://doi.org/10.1016/j.apcatb.2018.10.048; Content Type: article; Copyright: © 2018 Elsevier B.V. All rights reserved.