fig1

Figure 1. (A) Mo⁰/GDY structural evolution during catalysis; (B) HAADF-STEM image of Mo⁰/GDY samples; (C) Mo K-edge XANES profiles of Mo⁰/GDY and Mo foil (inset: derived first derivative curves); (D) NH₃ production performance for different batches of Mo⁰/GDY^[71]; (A-D) are reprinted with permission from reference^[71]. Copyright 2019 American Chemical Society; (E) Pd-GDY catalyst synthesis schematic; (F) HAADF-STEM results of Pd-GDY; (G) First derivative curves of Pd K-edge XANES spectra for Pd-GDY, PdO, and Pd foil; (H) Comparison of the catalytic performance of Pd-GDY with reported catalysts^[72]; (E-H) are reprinted with permission from reference^[72]. Reproduced under the CC BY license; (I) Schematic illustration of M SA/GDY (M = Rh, Ru, and Co); (J) HAADF-STEM image of Rh SA/GDY; (K) Schematic of the homemade pressurized NRR setup; (L) Performance comparison of Rh SA/GDY at different applied N₂ pressures^[73]; (I-L) are reprinted with permission from reference^[73]. Reproduced under the CC BY license; (M) NRR process on Ru SAs/GDY/G; (N) Imaging of Ru SAs/GDY/G by HAADF-STEM. Some Ru single atoms are highlighted with red rings; (O) FT k²-weighted χ^(k) function of the EXAFS spectra at the Ru K-edge of Ru SAs/GDY/G, Ru foil, RuCl₃, and RuO₂; (P) Catalytic performance of Ru SAs/GDY/G at different potentials^[74]; (M-P) are reprinted with permission from reference^[74]. Copyright 2023 American Chemical Society. GDY: Graphdiyne; HEB: hexaethynylbenzene; RHE: reversible hydrogen electrode; HAADF-STEM: high-angle annular dark field imaging in the aberration-corrected scanning transmission electron microscope; XANES: X-ray absorption near edge strucure; SA: single atom; NRR: nitrogen reduction reaction; FT: Fourier transform.