Magnetically Induced CO2 Methanation Using Exchange‐Coupled Spinel Ferrites in Cuboctahedron‐Shaped Nanocrystals

• Published in: Angewandte Chemie International Edition Vol. 59; no. 36; pp. 15537 - 15542
• Main Authors: Rivas‐Murias, Beatriz, Asensio, Juan M., Mille, Nicolas, Rodríguez‐González, Benito, Fazzini, Pier‐Francesco, Carrey, Julian, Chaudret, Bruno, Salgueiriño, Verónica
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 01.09.2020
• Edition: International ed. in English
• Subjects: Carbon dioxide; Catalysis; CO2 methanation; Cobalt ferrites; core–shell nanostructures; Heat exchange; Heating; Iron oxides; magnetic nanoparticles; Magnetic properties; Methanation; Nanocrystals; Nanoparticles; spinel ferrite
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.202004908

Magnetically induced catalysis can be promoted taking advantage of optimal heating properties from the magnetic nanoparticles to be employed. However, when unprotected, these heating agents that are usually air‐sensitive, get sintered under the harsh catalytic conditions. In this context, we present, to the best of our knowledge, the first example of air‐stable magnetic nanoparticles that: 1) show excellent performance as heating agents in the CO2 methanation catalyzed by Ni/SiRAlOx, with CH4 yields above 95 %, and 2) do not sinter under reaction conditions. To attain both characteristics we demonstrate, first the exchange‐coupled magnetic approach as an alternative and effective way to tune the magnetic response and heating efficiency, and second, the chemical stability of cuboctahedron‐shaped core–shell hard CoFe2O4–soft Fe3O4 nanoparticles. Core–shell ferrite nanoparticles for CO2 methanation: The magnetic properties of CoFe2O4 and CoFe2O4–Fe3O4 nanoparticles were controlled by the exchange‐spring magnetic approach. These nanoparticles showed excellent performance as air‐stable heating agents in CO2 methanation, resulting in CH4 yields above 95 %.