Pathways for SO2dissociation on Cu(100): density functional theory

The dissociation of SO(2) on Cu(100) and the diffusion of the co-adsorbed decomposition products S and O were investigated using density functional theory-based calculations. Two dissociation pathways were considered: (P1) [Formula: see text] and (P2) [Formula: see text], the difference being in the formation of the intermediate product SO. It is found that P1 is favored kinetically with a total effective dissociation barrier of 0.78 eV compared to P2 which has 1.58 eV. The transition state leading to the formation of O+SO is found to be a result of the weakened interaction between the O of SO and the surface while the transition state for breaking SO is seen to be that of the repulsive nature of co-adsorbed S and O. The co-adsorbed S has a lower diffusion barrier of 0.41 eV compared to O which has a barrier ranging from 0.49 to 0.95 eV.