Illuminating the Role of Mo Defective 2D Monolayer MoTe 2 toward Highly Efficient Electrocatalytic O 2 Reduction Reaction.

The fuel cell is one of the solutions to current energy problems as it comes under green and renewable energy technology. The primary limitation of a fuel cell lies in the relatively slow rate of oxygen reduction reactions (ORR) that take place on the cathode, and this is an all-important reaction. An efficient electrocatalyst provides the advancement of green energy-based fuel cell technology, and it can speed up the ORR process. The present work provides the study of non-noble metal-based electrocatalyst for ORR. We have computationally designed a 3 × 3 supercell model of metal defective (Mo-defective) MoTe 2 transition metal dichalcogenide (TMD) material to study its electrocatalytic activity toward ORR. This work provides a comprehensive analysis of all reaction intermediates that play a role in ORR on the surfaces of metal-deficient MoTe 2 . The first-principles-based dispersion-corrected density functional theory (in short DFT-D) method was implemented to analyze the reaction-free energies (Δ G ) for each ORR reaction step. The present study indicates that the ORR on the surface of metal-defective MoTe 2 follows the 4e - transfer mechanism. This study suggests that the 2D Mo-defective MoTe 2 TMD has the potential to be an effective ORR electrocatalyst in fuel cells.