Figure 4.

DFT simulations of the 2e-ORR pathway on 2H MoTe₂. (a) Optimized structure of HOO^* adsorbed on the basal plane or edge site; blue, orange, red and white spheres represent Mo, Te, O and H atoms, respectively. (b) ΔG_HOO^* for 2e-ORR to H₂O₂ on Pt [11], PtHg₄ [11], MoTe₂, MoSe₂ and MoS₂ at the equilibrium potential of U_O2/H2O2 = 0.70 V and the corresponding free-energy profiles. (c) ΔG_O^* of Pt [11], PtHg₄ [11], MoTe₂, MoSe₂ and MoS₂; the position of the dashed line (2.17 eV) denotes the average value of ΔG_O^* on Pt (typical 4e-ORR electrocatalyst) and PtHg₄ (typical 2e-ORR electrocatalyst), which was proposed to be the boundary between 4e and 2e selectivity. (d) 2D ‘heat map’ for 2e-ORR performance (both activity and selectivity); the dashed line represents the optimal ΔG_HOO^* for H₂O₂ production.