Multi-lattice Kinetic Monte Carlo Simulations from First Principles: Reduction of the Pd(100) Surface Oxide by CO

We present a multi-lattice kinetic Monte Carlo (kMC) approach that efficiently describes the atomistic dynamics of morphological transitions between commensurate structures at crystal surfaces. As an example, we study the reduction of a (root 5 x root 5)R27 degrees PdO(101) overlayer on Pd(100) in a CO atmosphere. Extensive density functional theory calculations are used to establish an atomistic pathway for the oxide reduction process. First-principles multi-lattice kMC simulations on the basis of this pathway fully reproduce the experimental temperature dependence of the reduction rate (Fernandes et al. Surf. Sci. 2014, 621, 31-39) and highlight the crucial role of elementary processes special to the boundary between oxide and metal domains.