Support Induced Effects on the Ir Nanoparticles Activity, Selectivity and Stability Performance under CO2 Reforming of Methane

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

doi:10.3390/nano11112880

Support Induced Effects on the Ir Nanoparticles Activity, Selectivity and Stability Performance under CO₂ Reforming of Methane

Nanomaterials (Basel). 2021 Oct 28;11(11):2880. doi: 10.3390/nano11112880.

Authors

Affiliations

¹ Laboratory of Physical Chemistry and Chemical Processes, School of Chemical and Environmental Engineering, Technical University of Crete, 73100 Chania, Crete, Greece.
² Energy and Environment Institute, University of Hull, Hull HU6 7RX, UK.
³ Department of Chemical and Process Engineering, University of Surrey, Guildford GU2 7XH, UK.
⁴ Department of Chemical Engineering, University of Patras, GR 265 04 Patras, Greece.
⁵ Energy & Bioproducts Research Institute (EBRI), Aston University, Aston Triangle, Birmingham B4 7ET, UK.
⁶ Department of Chemistry, Cambridge University, Cambridge CB2 1EW, UK.
⁷ Institute of Petroleum Research-Foundation for Research and Technology-Hellas (IPR-FORTH), 73100 Chania, Crete, Greece.

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-Al₂O₃, 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-Al₂O₃, 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-Al₂O₃ > 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).

Keywords: alumina-ceria-zirconia mixed oxides; carbon dioxide; coking-resistant catalysts; dry reforming of methane; greenhouse gases; iridium nanoparticles; sintering-resistant catalysts; syngas production.

Grants and funding

Τ2ΕΔΚ-00955/European Union and Greek national funds through the operational program 'Regional Excellence' and the operational program Competitiveness, Entrepreneurship and Innovation, under the call "RESEARCH-CREATE-INNOVATE"