RESEARCH / A0590
Atomic-Level Engineering Fe1N2O2 Interfacial Structure Derived from Oxygen-Abundant Metal–Organic Frameworks to Promote Electrochemical CO2 Reduction
Read the original paper · 10.1039/d2ee00878e ↗
Source figures may contain other techniques and soft X-ray spectra. C, N and O measurements are outside our current hard-XAFS testing range.
Fig. 2 (a) O 1s XPS spectra and (b) N K-edge XANES spectra for Fe1N2O2/NC and NC. p-N, py-N, g-N and o-N represent pyridinic N, pyrrolic N, graphite and oxidized N, respectively. (c) Fe K-edge XANES spectra. Linear fitting curve derived from the corresponding Fe K-edge XANES spectra. (d) FT-EXAFS of the Fe K-edge. (e) WT for the k3-weighted Fe K-edge EXAFS signals in Fe1N2O2/NC, FePc and Fe2O3. (f) FT-EXAFS fitting curve for Fe1N2O2/NC. (g) The experimental and the calculated XANES data. (h) The atomic structure model for the Fe1N2O2/NC catalysts. Schematic model, Fe (yellow), N (blue), C (gray) and O (red).
Fig. 3 (a) N2 adsorption–desorption isotherms of Fe/Zn-MOF-74, M@Fe/Zn-MOF-74 and Fe1N2O2/NC catalysts (the isotherms of Fe/Zn-MOF-74, and Fe1N2O2/NC catalysts were offset vertically by 750, and 500 cm3 g1 STP, respectively). Insets: Their corresponding pore size distribution curves. (b) The proposed formation mechanism of the Fe1N2O2/NC and Fen/C catalysts. (c) N 1s XPS spectra of the intermediates at different pyrolysis stages of M@Fe/ Zn-MOF-74. (d) Fe K-edge XANES spectra. (e) FT-EXAFS of Fe K-edge. (f) FT-EXAFS fitting curves for Fe K-edge. Inset: The models of Fe coordination configurations during the pyrolysis process.