A universal picture for ejecting atoms on metallics

The surface-site stability of transition metals and alloys, which can be measured by the ejection energy, is essential in corrosion and electrocatalysis . However, the complex geometric and alloying effects of alloys prohibit the accurate estimation of ejection energies. Herein we introduce the geometric and electronic gradients and cohesive properties of surface sites to determine the ejection energy for transition metals, single-atom alloys, binary alloys, near-surface alloys, and high-entropy alloys. This predictive model reveals not only the electronic and geometric determinants of interatomic bonding in alloys but also the range-reaching characters of alloying and geometric variation, which outlines explicitly the commonality and difference between different alloys in bonding. Our model uncovers a novel physical picture for the interatomic bonding of alloys, provides a simple way to estimate the alloying effect, and is helpful for modulating the stability of alloy surfaces.