The design of solid metal catalysts using theoretical methods has been a long-standing goal in heterogeneous catalysis.[1, 2] Recent developments in methodology and computer technology as well as the establishment of a descriptor-based approach for the analysis of reaction mechanisms and trends across the periodic table allow for the fast screening for new catalytic materials and have lead to first examples of computational discoveries of new materials.[3-8] The underlying principles of the descriptor-based approach are the existence of relations between the surface electronic structure, adsorption energies and activation barriers that result in volcano-shaped activity plots as function of simple descriptors, such as atomic binding energies or the d-band center.[1, 6, 9-17] Linear scaling relations have been established between the adsorption energies of hydrogen-containing molecules such as CHx, NHx, OHx and SHx and the C, N O and S adsorption energies on transition-metal surfaces.[18] Transition-state energies have also been shown to scale linearly with adsorption energies in a similar fashion.[9, 16, 19, 20] Recently, a single transition state scaling relation