Magnetic Ferrite-Based Materials as Electrocatalysis for Energy Applications

The current energetic paradigm for the energy production is based on the consumption (combustion) of traditional petroleum-derived fossil fuels. The growing attention toward the green energy transition has made the search for alternative technological solutions an essential current task. In this context, magnetic spinel ferrites are gaining significant attention in the catalysis due to their intrinsic properties,[1] which make them ideal candidates as Pt group-free catalysts exploitable in the photo(electro)catalytic production of H2 (i.e., the most interesting clean energy carrier) through hydrogen evolution reaction (HER).[2-3] Hence, in the present study, magnetic CuFe2O4, CoFe2O4, ZnFe2O4 and mixed Cu1-xCox or Cux-1Znx ferrite systems were synthesised following a soft-chemistry approach followed by a calcination step. After performing morphological, structural, physicochemical, and magnetic characterisations, the most promising magnetic materials were tested in HER process, obtaining promising results, especially in terms of selectivity toward the desired product. The amount of Co or Zn in the mixed systems has been optimized allowing to obtain, under light irradiation, an impressive FE% of almost 100% for the best sample. Additionally, hybrid materials with magnetic features were produced following a properly modified Stöber method by covering the surface of some selected magnetic ferrite-based materials with CuO, a very active electrocatalyst, able to favour the reduction of CO2 (CO2R) into a plethora of industrially valuable C1-C2+ chemicals and fuels.[4-5] These magnetic hybrids were fully characterised, and tested in (electro)catalytic CO2R processes showing, although preliminary, interesting performances.