fig2

Figure 2. (A, B) TEM images of (Co₁→Cop)/N-CNTs; (C) HAADF-STEM image of (Co₁→Cop)/N-CNTs in the nanoparticle free region, where single Co atoms are clearly seen; (D) Schematic Illustration for the Synthesis of (Co₁→Cop)/N-CNTs from ZnCo-ZIF; (E) Schematic Illustration of HMF Conversion to FDCA Accelerated by Different Reactive Sites (Co₁ and Cop); (F) Reaction Routes for the Aerobic Oxidation of HMF to FDCA^[46]. Copyright 2022 American Chemical Society. TEM: Transmission electron microscopy; CNTs: carbon nanotubes; HAADF-STEM: high-angle annular dark-field scanning TEM; HMF: 5-hydroxymethylfurfural; FDCA: 2,5-furandicarboxylic acid.