Supported metal catalysts are comprised of small metal nanoparticles dispersed on the surface of a support material. Previously, the role of the support oxide was commonly thought to be limited to provide large metal surface areas. However, it is now generally accepted that the activity and selectivity of these catalysts are dependent on the type and composition of the support used [1][2][3] or even on thermal pretreatment conditions of catalysts consisting of the same metal and support [4]. In other words, the role of the support goes well beyond strictly physical phenomena such as increasing the surface area, and the specific interaction of the support with the active phase often controls the course of a catalytic reaction.Understanding the effect of the support oxide on the properties of metal nanoparticles is a challenging subject because it opens a way towards modeling and tuning of the catalytic properties by a deliberate choice of the support oxide [5][6][7][8]. As a consequence, gaining an insight into the interfacial structure between metal nanoparticles and their support, particularly under relevant reaction conditions, has been an important topic in the field of heterogeneous catalysis for decades [9,10]. Therefore,