Principles determining the activity of magnetic oxides for electron transfer reactions

On the Role of Ferromagnetic Interactions in Highly Active Mo‐Based Catalysts for Ammonia Synthesis

“…We observe that the enhanced catalytic activity in FM X 3 Mo 3 N 1‐δ compositions is due to similar electronic and magnetic factors as previously anticipated in strongly correlated oxides . The principles of spintro‐catalysis seem to be valid and applicable to all catalysts including earth‐abundant 3d ‐magnetic metals.…”

“…), while Ni 2 Mo 3 N is nonmagnetic, as reported by other authors ,. These kind of compositions are also active for oxygen reduction; and nitrogen fixation has similarities with O 2 reduction as the double bond in oxygen molecule must be activated by incoming electrons in a similar way as the triple bond of nitrogen molecule. In both cases, electrons are to be incorporated into π* molecular orbitals prior to the immobilization of protons.…”

“…Spin‐dependent potentials are decisive for the kinetics of electron transfer reactions at magnetic interphases ,. Catalysts with preferential ferromagnetic (FM) exchange interactions are optimized on the basis of energy shells antisymmetric in space, ψ antisym , being distinguished as “spintro‐catalysts” . The studies performed so far on magnetic catalysts have focused on oxygen electrochemistry, revealing the importance of quantum exchange interactions (QEI), as well as their implications for the understanding and developing of efficient energy technologies.…”

“…The studies performed so far on magnetic catalysts have focused on oxygen electrochemistry, revealing the importance of quantum exchange interactions (QEI), as well as their implications for the understanding and developing of efficient energy technologies. However, the interest and applicability of novel concepts like FM enhanced covalent bonds, reduced Coulomb interactions and spin‐sensitive reaction steps in compositions with ψ antisym is wider, and might be extended to other relevant chemical processes, as it is the case of nitrogen fixation to produce ammonia …”

“…The Perde‐Burke‐Ernzerhof exchange‐correlation DFT functional revised for solids was used for all calculations . In order to properly describe on‐site Coulomb interactions of localised d electrons, DFT+U methodology was used, with values of U=2.0 for Co and 4.0 for Fe, as previously reported ,. Images were produced with VESTA …”