Dielectric barrier plasma discharge exsolution of nanoparticles at room temperature and atmospheric pressure

Haq, Atta ul and Fanelli, Fiorenza and Bekris, Leonidas and Martin, Alex Martinez and Lee, Steve and Khalid, Hessan and Savaniu, Cristian D. and Kousi, Kalliopi and Metcalfe, Ian S. and Irvine, John T. S. and Maguire, Paul and Papaioannou, Evangelos I. and Mariotti, Davide (2024) Dielectric barrier plasma discharge exsolution of nanoparticles at room temperature and atmospheric pressure. Advanced Science. 2402235. ISSN 2198-3844 (https://doi.org/10.1002/advs.202402235)

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Abstract

Exsolution of metal nanoparticles (NPs) on perovskite oxides has been demonstrated as a reliable strategy for producing catalyst-support systems. Conventional exsolution requires high temperatures for long periods of time, limiting the selection of support materials. We report plasma direct exsolution at room temperature and atmospheric pressure of Ni NPs from a model A-site deficient perovskite oxide (La0.43Ca0.37Ni0.06Ti0.94O2.955). Plasma exsolution is carried out within minutes (up to 15 min) using a dielectric barrier discharge configuration both with He-only gas as well as with He/H2 gas mixtures, yielding small NPs (< 30 nm diameter). To prove the practical utility of exsolved NPs, we have carried out various experiments aimed at assessing their catalytic performance for methanation from synthesis gas, CO and CH4 oxidation. We successfully demonstrated low-temperature and atmospheric pressure plasma exsolution and suggest that this approach could contribute to the practical deployment of exsolution-based stable catalyst systems.