First-principles study on the catalytic role of Ag in the oxygen adsorption of LaMnO3(0 0 1) surface

In the present paper, the catalytic role of Ag in the oxygen adsorption of LaMnO3(0 0 1) surface has been theoretically investigated using first-principles calculations based on the density functional theory (DFT) and pseudopotential method. The O2 adsorption energy is larger for the vertical adsorption and the covalent bond was formed between O2 molecule and surface Mn. The calculation of electronic properties of interaction between Ag atom and LaMnO3(0 0 1) surface demonstrates that the most stable position for Ag adsorption is hollow site. The O2 adsorption energy dramatically increased from 0.298 eV to 1.108 eV due to Ag pre-adsorbed. It is Ag pre-adsorbed that facilitates O2 adsorption on surface. The bond length and bond population of O2 molecule indicate that Ag atom facilitates O2 molecule dissociative adsorption. The Ag atom strengthens LaMnO3(0 0 1) substrate activity and activity center was formed on surface, which enhances the electrocatalytic activity of LaMnO3 as solid oxide fuel cells cathode material at low temperature.