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

Angew Chem Int Ed Engl. 2020 Sep 1;59(36):15537-15542. doi: 10.1002/anie.202004908. Epub 2020 Jul 29.

Abstract

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 CoFe2 O4 -soft Fe3 O4 nanoparticles.

Keywords: CO2 methanation; core-shell nanostructures; magnetic nanoparticles; spinel ferrite.