Support induced effects on the ir nanoparticles activity, selectivity and stability performance under CO<inf>2</inf> reforming of methane

Nikolaraki, Ersi; Goula, Grammatiki; Panagiotopoulo, Paraskevi; Taylor, Martin J.; Kousi, Kalliopi; Kyriakou, Georgios; Kondarides, Dimitris I.; Lambert, Richard M.; Yentekakis, Ioannis V.

Abstract

The production of syngas (H2 and CO)—a key building block for the manufacture of liquid energy carriers, ammonia and hydrogen—through the dry (CO2 −) reforming of methane (DRM) continues to gain attention in heterogeneous catalysis, renewable energy technologies and sustainable economy. Here we report on the effects of the metal oxide support (γ-Al2 O3, alumina-ceria-zirconia (ACZ) and ceria-zirconia (CZ)) on the low-temperature (ca. 500–750◦ C) DRM activity, selectivity, resistance against carbon deposition and iridium nanoparticles sintering under oxidative thermal aging. A variety of characterization techniques were implemented to provide insight into the factors that determine iridium intrinsic DRM kinetics and stability, including metal-support interactions and physicochemical properties of materials. All Ir/γ-Al2 O3, Ir/ACZ and Ir/CZ catalysts have stable DRM performance with time-on-stream, although supports with high oxygen storage capacity (ACZ and CZ) promoted CO2 conversion, yielding CO-enriched syngas. CZ-based supports endow Ir exceptional anti-sintering characteristics. The amount of carbon deposition was small in all catalysts, however decreasing as Ir/γ-Al2 O3 > Ir/ACZ > Ir/CZ. The experimental findings are consistent with a bifunctional reaction mechanism involving participation of oxygen vacancies on the support’s surface in CO2 activation and carbon removal, and overall suggest that CZ-supported Ir nanoparticles are promising catalysts for low-temperature dry reforming of methane (LT-DRM).

Citation

Nikolaraki, E., Goula, G., Panagiotopoulo, P., Taylor, M. J., Kousi, K., Kyriakou, G., Kondarides, D. I., Lambert, R. M., & Yentekakis, I. V. (2021). Support induced effects on the ir nanoparticles activity, selectivity and stability performance under CO2 reforming of methane. Nanomaterials, 11(11), Article 2880. https://doi.org/10.3390/nano11112880

• Journal Article Type: Article
• Acceptance Date: Oct 25, 2021
• Online Publication Date: Oct 28, 2021
• Publication Date: Nov 1, 2021
• Deposit Date: Oct 29, 2021
• Publicly Available Date: Oct 29, 2021
• Journal: Nanomaterials
• Print ISSN: 2079-4991
• Electronic ISSN: 2079-4991
• Publisher: MDPI
• Peer Reviewed: Peer Reviewed
• Volume: 11
• Issue: 11
• Article Number: 2880
• DOI: https://doi.org/10.3390/nano11112880
• Keywords: Greenhouse gases; Dry reforming of methane; Carbon dioxide; Alumina-ceria-zirconia mixed oxides; Iridium nanoparticles; Coking-resistant catalysts; Sintering-resistant catalysts; Syngas production
• Public URL: https://hull-repository.worktribe.com/output/3865403
• Publisher URL: https://www.mdpi.com/2079-4991/11/11/2880