A Density Functional Theory Study of the Two-Dimensional Bis(iminothiolato)metal Monolayers as Efficient Electrocatalysts for Oxygen Reduction Reaction

摘要

In recent years, two-dimensional metal-organic frameworks (MOF)-derived heteroatom-doped carbon-based electrocatalysts have drawn extensive attention due to the superior catalytic activity for oxygen reduction reaction (ORR). In this work, the ORR catalytic activity of a series of bis(iminothiolato)metal (TMIT) (TM = Mn, Fe, Co, Ni, Cu, Ru, Rh, Pd, Ir, and Pt) monolayers has been investigated by using the density functional method. The scaling relations are obtained between the Gibbs adsorption free energies of the oxygenated intermediates. The volcano plot of the ORR activity between Delta G(*OH) and overpotential is established. The results reveal that FeIT possesses the best ORR activity. The predicted overpotential is 0.52 V for FeIT, close to 0.45 V for pure Pt. The migration of an 0 atom from the S site to the Fe top site is the rate-determining step with an energy barrier of 0.59 eV, smaller than 0.80 eV for pure Pt. This work may provide an effective method for the design of high-performance ORR catalysts by using the two-dimensional MOFs.