fig2

Figure 2. (A) Schematic illustration of cathodic and anodic deposition of Ir species^[39]; (B) Energies and models of intermediates and transition states in the stepwise preparation mechanism of Pd₁/TiO₂^[42]; (C) First-run reaction performances for Pd₁/TiO₂, Pd/C, and H₂PdCl₄. in benzaldehyde hydrogenation^[42]; (D) Schematic illustration of the synthesis of single-atom Pd₁/graphene catalyst via ALD^[47]; (E) Schematic illustration for preparation of Ru₁/NC-T catalysts^[52]; (F) Schematic illustration of synthesizing Pd₁@HEFO^[55]; (G) The schematic diagram shows the HT-SA synthesis and dispersion process (grey, carbon atoms; cyan, metal precursor; red, metallic atoms)^[63]. ALD: Atomic layer deposition; HEFO: high-entropy fluorite oxide; HT-SA: high-temperature-synthesized single atoms.