Theoretical Study On The Application Of Metal Nitrides Supported By Two-dimensional Materials For The Design Of Oxygen Electrode Catalysts

Since the rapid development of human society,the increasing consumption of fossil fuels has caused many serious problems,such as the energy crisis and global environmental pollution.Developing efficient and stable energy conversion and storage devices to replace the traditional fossil fuel has been widely revealed as a promising strategy to solve the above problems.In this respect,fuel cells,metal-air cells,and water splitting system have attracted considerable interest as promising clean energy technologies due to their high energy conversion efficiency,high energy density,and low greenhouse gas emissions.However,the practical applications of these above devices significantly depend on the efficiency of the oxygen electrode reactions,including oxygen reduction reaction（ORR）and oxygen evolution reaction（OER）owing to their sluggish kinetics,multi-step proton coupled electron transfer,and high overpotential.To this end,searching for highly efficient cathode electrocatalysts to boost the ORR and OER is highly urgent.In this paper,we investigated the electrocatalytic potential of single transition metal atom supported on pyrrolic N-doped graphene,phthalocyanine material and N-doped Mo S₂ materials for OER/ORR processes,respectively,the results are shown below the results are shown below:（1）By means of comprehensive density functional theory computations,we proposed a new class of OER catalyst,i.e.,TMN₃@Mo S₂,in which several TMN₃moieties was embedded into Mo S₂ monolayer.The ab-initio molecular dynamics simulations,dissolution potential,and diffusion barrier calculations show that the systems have good stability.In additon,the Ni N₃@Mo S₂ exhibit the best OER catalytic activity due to its ultralow overpotential of 0.45 V for OER.The local structura and chemical environment of the reaction site can well rationalize the origin of the high catalytic activity of Ni N₃@Mo S₂ for the OER.（2）We systematically explored the potential of pyrrolic-N doped graphene（pyrrolic-N₄-G）supported various transition metal atoms as electrocatalysts for the ORR and OER.Our results revealed that these candidates exhibit high electrochemical stability.Especially,the Ir/pyrrolic-N₄-G can perform as a promising bifunctional electrocatalyst for ORR/OER with the low overpotentials.Interestingly,multiple-level descriptors,including energy descriptor,structure descriptor,and-band center can well rationalize the origin of the high catalytic activity of Ir/pyrrolic-N₄-G for the ORR/OER.（3）We systematically explored the potential of a series of transition metal anchored on the phthalocyanine（TM-Pc）as electrocatalysts for ORR/OER.The calculation results revealed that these candidates exhibit high electrochemical stability and thermodynamic stability.More importantly,the Ir-Pc catalyst can perform as a promising bifunctional electrocatalyst for ORR/OER due to its ultralow overpotentials,which can be well rationalized by multiple descriptors from energetic and electronic properties.