First-principles statistical mechanics study of the stability of a   sub-nanometer thin surface oxide in reactive environments: CO oxidation at   Pd(100)
  We employ a multiscale modeling approach to study the surface structure and composition of a Pd(100) model catalyst in reactive environments. Under gas phase conditions representative of technological CO oxidation (~1 atm, 300-600 K) we find the system on the verge of either stabilizing sub-nanometer thin oxide structures or CO adlayers at the surface. Under steady-state operation this suggests the presence or continuous formation and reduction of oxidic patches at the surface, which could be key to understand the observable catalytic function. 
Jutta Rogal, Karsten Reuter, and Matthias Scheffler