An oxygen-coordinated molybdenum single atom catalyst for efficient electrosynthesis of ammonia

Figure 1. Schematic illustration of the synthetic process of Mo-SAs/AC.Figure 2. (a) Low-magnification TEM image. The inset shows the corresponding SAED pattern. Low- and (c) high-magnification aberrationcorrected HAADF-STEM images of Mo-SAs/AC. (d) HAADF-STEM image and the corresponding elemental mapping images of Mo-SAs/AC. (a) Nitrogen adsorption–desorption isotherm and pore size distribution curve (inset) of Mo-SAs/AC. (b) Normalized Mo K-edge XANES spectra and (c) FT-EXAFS curves of the Mo foil, MoO3 and Mo-SAs/AC. (d) Mo 3d XPS spectrum of Mo-SAs/AC.Figure 3. (a) Nitrogen adsorption–desorption isotherm and pore size distribution curve (inset) of Mo-SAs/AC. (b) Normalized Mo K-edge XANES spectra and (c) FT-EXAFS curves of the Mo foil, MoO3 and Mo-SAs/AC. (d) Mo 3d XPS spectrum of Mo-SAs/AC.Figure 4. (a) LSV curves of the Mo-SAs/AC catalyst in Ar- or N2-saturated 0.1 M Na2SO4 solution. (b) NH3 yield rate and faradaic efficiency of Mo-SAs/AC obtained at different potentials for 2 h NRR measurement. (c) 10 h durability test for Mo-SAs/AC toward the NRR at 0.40 V vs. RHE. (d) Recycling tests for Mo-SAs/AC during the NRR at 0.40 V vs. RHE.