A potentially efficient ORR catalyst: Transition metal-doped 2D Haeckelite MoS2

Abstract

Enhancing the efficiency of the proton exchange membrane fuel cell (PEMFC) relies significantly on the development of low-cost but highly efficient catalysts for oxygen reduction reaction (ORR). In the present work, a specially structured two-dimensional layered material called Haeckelite (HL) MoS2 is investigated as an electrocatalyst for ORR by using density functional theory (DFT). In order to further improve the ORR catalytic performance, transition metals (TMs = Mn, Ru, Rh and Os) are independently doped on the surface of HL-MoS2. The detailed calculation includes the TMs doping, O2 molecule adsorption, electronic structure analysis, and Gibbs free energy comparison. The final results demonstrate that all TM/HL-MoS2 systems exhibit metallic properties, especially Ru/HL-MoS2 has the best catalytic performance for ORR in view of its moderate adsorption energy of O2 molecule (≈ 0.57 eV) and the lowest overpotential (≈ 0.503 V). Therefore, the combination of defect structure and TMs doping in MoS2 can be regarded as an effective approach to achieve both enhancement of catalytic performance and reduction of consumption of precious metals in the oxygen reduction reaction.