The understanding of quantum correlations within catalysts is an active and advanced research field, absolutely necessary when attempting to describe all the relevant electronic factors in catalysis. In our previous research, we came to the conclusion that the most promising electronic interactions to improve the optimization of technological applications based on magnetic materials are quantum spin exchange interactions (QSEI), nonclassical orbital mechanisms that considerably reduce the Coulomb repulsion between electrons with the same spin. QSEI can stabilize open-shell orbital configurations with unpaired electrons in magnetic compositions. These indirect spin-potentials significantly influence and differentiate the catalytic properties of magnetic materials. As a rule of thumb, reaction kinetics (thus catalytic activity) generally increase when interatomic ferromagnetic (FM) interactions are dominant, while it sensibly decreases when antiferromagnetic (AFM) interactions prevail. The influence of magnetic patterns and spin-potentials can be easily spotted in several reactions, including the most important biocatalytic reactions like photosynthesis, for instance. Moreover, we add here the concept of quantum excitation interactions (QEXI) as a crucial factor to establish the band gap in materials and as a key factor to efficiently mediate electron transfer reactions. In the present Perspective, we offer a general conceptual overview, mainly based on our recent research, on the importance of strongly correlated electrons and their interactions during catalytic events. We present the physical principles and meanings behind quantum exchange in a way that facilitates a comprehensive understanding of the electronic interactions in catalysis from their quantum roots; we explore the issue via mathematical treatment as well as via intuitive visual space/time diagrams to expand the potential readership beyond the domain of physicists and quantum chemists.

One of the main obstacles in the implementation of hydrogen fuel cells (HFC) lies in the efficiency loss due to the overpotential of the oxygen reduction reaction (ORR). Nowadays, the best catalysts for cathodes in HFC are Pt 3 Co nanostructures. The superior activity of these magnetic Pt-alloys, compared to metallic platinum, correlates with the milder chemisorption of the oxygenated intermediates on the surfaces of the alloy. Quantum spin exchange interactions (QSEI), including interlayer exchange coupling due to magnetic inner Co layers, are determinant to make the active sites prone to bind adsorbed oxygen atoms in an optimal fashion for catalytic activity. We present a study on antiferromagnetic (AFM) and ferromagnetic (FM) Pt 3 Co (111) nanostructures conducted via spin-polarized DFT+U calculations. The study begins with a thorough screening of AFM, FM, and fictitious closed-shell Pt 3 Co slab models with different atomic distributions ranked in order of stability. The chemisorption enthalpy values of O* and H* atoms on the most stable AFM (A-type) and FM nanolayers show weaker binding of the adsorbate compared to isostructural Pt (111) nanolayers. Cooperative spin potentials, associated with open-shell orbital configurations, unequivocally lead to decreased enthalpies of adsorption for H* and O* atoms. Hence, a complete and realistic treatment of the structure−activity relationships in heterogeneous catalysis relies upon the correct evaluation of orbital magnetism: spin-dependent potentials are key factors to design optimal ORR catalysts.

The definition of the interplay between chemical composition, electro-magnetic configuration and catalytic activity requires a rational study of the orbital physics behind active materials.

Two gold(I)-based metallo-tweezers with bis(Au-NHC) pincers and a carbazole connector have been obtained and used for the recognition of polycyclic aromatic hydrocarbons (PAHs). In the case of the tweezer with pyrene-NHC ligands, the presence of the pyrene fragment and the N-H bond in the carbazole linker enable the receptor to show significant enhanced binding abilities toward PAHs functionalized with H-bonding groups, through combined π-π stacking and H-bonding.