Extended Data Fig. 4: Nature of Pt species in Pt/CeOx/SiO2 catalyst.
From: Functional CeOx nanoglues for robust atomically dispersed catalysts
a,b,c, HAADF images of the as-synthesized 0.4 wt% Pt/CeOx/SiO2 catalyst. d, HAADF image of a high-loading Pt/CeOx/SiO2 catalyst, which was fabricated by impregnation and reduced in H2 at 300 °C for 1 h, shows presence of small Pt clusters. e–j, EXAFS results characterizing the as-synthesized 0.4 wt% Pt/CeOx/SiO2. e, k1-weighted experimental EXAFS function (black solid line) and the sum of the calculated Pt–O, Pt–Olong and Pt–O–Ce contributions (red dashed line). f, Imaginary part and the magnitude of Fourier transform (k1-weighted) of the experimental EXAFS results (black solid line) and sum of the calculated Pt–O, Pt–Olong and Pt–O–Ce contributions (red dashed line). g–i, Imaginary part and magnitude of Fourier transform (phase- and amplitude-corrected) of the experimental results (black solid line) and the calculated contributions (red dashed line) of the Pt–O shell (k1-weighted) (g), the Pt–Olong shell (k1-weighted) (h), and the Pt–O–Ce shell (k3-weighted) (i). j, Summary of the EXAFS parameters. CN, coordination number; R, distance between absorber and backscatterer atoms; Δσ2, disorder term; ΔE0, inner potential correction. Error bounds (accuracies) characterizing the structural parameters obtained by EXAFS spectroscopy are estimated to be CN, ±10%; R, ±0.02 Å; Δσ2, ±20%; ΔE0, ±20%.
