Extended Data Fig. 9: Characterization and CO oxidation performance of the as-synthesized and activated catalysts.
From: Functional CeOx nanoglues for robust atomically dispersed catalysts
a,b, CO oxidation catalysis: light-off curves characterizing 0.3 wt% Pt/CeO2 (5 mg of catalyst mixed with 25 mg of SiO2) (a) and 0.4 wt% Pt/CeO2 NPs/SiO2 (30 mg) (b). Activation conditions: H2 at 300 °C for 1 h. c, Light-off curves of 4 wt% Pt/CeOx/SiO2 (3 mg of catalyst mixed with 27 mg of SiO2; pretreated in H2 at 400 °C for 3 h to form Pt clusters). d–g, CO oxidation light-off data and CO-DRIFTS spectra characterizing 0.4 wt% Pt/CeOx/SiO2 (IMP) (d,e) and Pt/SiO2 (IMP) catalyst (f,g). h, Light-off temperatures T50 (50% CO conversion) of various catalysts: as-synthesized 0.4 wt% Pt/CeOx/SiO2 (A), activated 0.4 wt% Pt/CeOx/SiO2 (B), activated Pt/CeO2 (C), activated Pt/CeO2 NPs/SiO2 (D), activated 4 wt% Pt/CeOx/SiO2 (E), activated Pt/CeOx/SiO2 by impregnation (F) and activated Pt/SiO2 by impregnation (G). i, In situ Pt LIII XANES spectra of 0.4 wt% Pt/CeOx/SiO2 catalyst during activation in 10% H2/He. j, Ex situ Pt LIII XANES spectra collected at room temperature characterizing the 0.4 wt% Pt/CeOx/SiO2 catalyst before/after reduction at 300 °C for 1 h; data characterizing Pt foil are included for comparison. k–o, EXAFS results characterizing the activated 0.4 wt% Pt/CeOx/SiO2 catalyst. k, 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). l, 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). m–o, Imaginary part and magnitude of Fourier transform (phase- and amplitude-corrected) of the data (black solid line) and the calculated contribution (red dashed line) of the Pt–O shell (k1-weighted) (m), the Pt–Olong shell (k1-weighted) (n), and the Pt–O–Ce shell (k3-weighted) (o). p, Summary of the EXAFS parameters. CN, coordination number; R, distance between absorber and backscatterer atoms; Δσ2, disorder term; ΔE0, inner potential correction. q, Apparent activation energy (Ea) for CO oxidation characterizing the as-synthesized and reduced 0.4 wt% Pt1/CeOx/SiO2. r, Long-term stability test of the activated 0.4 wt% Pt1/CeOx/SiO2 at a reaction temperature of 140 °C. s, HAADF image of the 0.4 wt% Pt1/CeOx/SiO2 after stability test. t, Long-term stability test of the activated 0.3 wt% Pt/CeO2 at 140 °C.
