fig8

From: Layered double hydroxide-based single-atom catalysts: precise catalyst design on a two-dimensional ‘atomic canvas’

Figure 8. (A) Fourier-transformed Ru K-edge EXAFS spectra of Ru/CoFe-LDHs, RuCl₃, RuO₂, and Ru metal; (B) Corresponding model-based fittings of Ru EXAFS for Ru/CoFe-LDHs and simulated EXAFS spectra from Ru-O and Ru-O-M (M = Co or Fe) bonds (the inset is the magnifying local structure of Ru/CoFe-LDHs), showing the exclusive existence of Ru-O-M bonds in Ru/CoFe-LDHs sample. The differential charge density of elements in CoFe-LDHs (C) and Ru/CoFe-LDHs (D) from computational simulation, revealing electron donation from LDHs to Ru. Gibbs free-energy diagram for the four steps of OER on CoFe-LDHs (E) and Ru/CoFe-LDHs (F). (A-F) Reprinted with permission from Ref.^[43]. Copyright 2019, Springer Nature. EXAFS: Extend X-ray absorption fine structure; LDH: layered double hydroxide.