Reactivity of transition-metal alloys to oxygen and sulfur

Abstract

Oxidation and tarnishing are the two most common initial steps in the corrosive process of metals at ambient conditions. These are always initiated with O and S binding to a metallic surface, so that one can use the binding energy as a rough proxy for the metal reactivity. With this in mind, we present a systematic study of the binding energy of O and S across the entire transition-metals composition space, namely we explore the binding energy of {\bf 88} single-phase transition metals and of {\bf 646} transition-metal binary alloys. The analysis is performed by defining a suitable descriptor for the binding energy. This is here obtained by fitting several schemes, based on the original Newns-Anderson model, against density-functional-theory data for the 4$d$ transition metal series. Such descriptor is then applied to a vast database of electronic structures of transition-metal alloys, for which we are able to predict the range of binding energies across both the compositional and the structural space. Finally, we extend our analysis to ternary transition-metal alloys and identify the most resilient compounds to O and S binding.