Strategies to break linear scaling relationships

The search for new catalytic materials has relied on highly time- and human- resource-consuming procedures. The appearance of theoretical methods that employ density functional theory coupled to kinetic models has allowed the rational understanding of activity volcano plots and selectivity abrupt profiles that resemble cliffs. However, these methodologies present several drawbacks as the optimization is confined to a family of materials, typically metals, and not applied to the overall phase and compositional space, therefore the maximum activity might not be sufficient for practical applications. Volcanos emerge from the symmetry between the adsorption energies of different intermediates on the catalyst, and thus circumventing these dependencies is crucial to identify better catalytic materials. Here we present a revision of the advances in the field that indicate that complexity in the materials is key to identifying alternative paths and thus overcome the drawbacks of scaling relationships. The energies of the species in a given reaction network are linked by linear scaling relationships, limiting the design of catalysts with improved activity and selectivity. In this Perspective, López and Pérez-Ramírez discuss strategies to circumvent such scaling relationships.