Figure 17.

(a) Schematic diagram of the catalytic mechanism of metal oxide HNSs@C for the hydrogenation of 4-NP reaction. Figure reproduced from ref. [207]. SEM images of (b) Fe₂O₃, (c) FeCa5, (d) FeCa10, and (e) FeCa20. Figure reproduced from ref. [209]. SEM images of (f) FeMn10, (g) FeMn20, (h) FeMn40, and (i) FeMn80 (represent the molar ratios of Mn/(Fe + Mn) are ~10, 20, 40, and 80 mol%). Figure reproduced from ref. [22]. (j) Proposed reaction routes of o-DCB catalytic oxidation over ZnCe5 (doped with 5 mol% Ce). Figure reproduced from ref. [210].