1. Introduction

The adsorption and dissociation of CO on metal surfaces has become representative in surface science as the workhorse for fundamental studies in industrial catalysis [1]. Within the last few years, giant strides have been taken in the theory of surface chemical reactivity, including the elucidation of the fundamental nature of CO activation on transition and noble metal surfaces, categorised as a late-transition state structure-sensitive reaction [2] that follows the universality principle [3]. Structure sensitivity makes reference to the role of active sites at surfaces (steps, kinks, edges and corners) on lowering reaction barriers whereas the concept of universality principle relies on establishing linear relations between activation barriers and product adsorption energies