Effect of Adatom Doping on the Electrochemical Performance of 1T′-MoS₂ for Oxygen Reduction Reactions

Abstract

Two-dimensional transition-metal-dichalcogenides (TMDs) have received great attention for their structural polymorph and attractive electronic and electrocatalytic properties. However, pristine 2D TMDs generally exhibit low catalytic activity toward oxygen reduction reactions (ORRs). Here, we explored the potential of transition metal-doped octahedral 1T′-MoS2 for ORRs by density functional theory computations. Interestingly, the linear scaling correlation is significantly weakened in the series of M@1T′-MoS2 catalysts, which is likely due to the fluxional behavior of the metal center that depends strongly on the bound adsorbates. Compared with the activity of pristine 1T′-MoS2, most of the metal-doped 1T′-MoS2 catalysts effectively promote the ORR activity. Particularly, Co@1T′-MoS2 is screened out to exhibit excellent activity with an ultralow overpotential of 0.34 V, which rivals state-of-the-art Pt-based materials. Electronic structure analysis further demonstrates that the Co dopant can effectively activate O2 and promote the ORR activity. Our calculation results provide feasible methods for designing efficient and low-cost ORR catalysts.