RESEARCH / A0243
Fe–N–C Electrocatalyst with d-π Interaction Induced by Submicropore Vacancies for Durable Oxygen Reduction Reaction in Proton-Exchange Membrane Fuel Cells
Read the original paper · 10.1021/acscatal.5c06689 ↗
Source figures may contain other techniques and soft X-ray spectra. C, N and O measurements are outside our current hard-XAFS testing range.
Figure 2. (a) Nitrogen adsorption and desorption isotherms (insets: pore size distribution), (b) XRD patterns, XPS spectra of (c) N 1s and (d) Fe 2p, (e) EPR spectra, (f) Fe K-edge XANES spectra, and (g) the corresponding estimated valence states of Fe−N−C with various pore structures.
Figure 3. Coordination environment characterization of Fe−N−Cs with various pore structures: FT k3-weighted Fe K-edge EXAFS spectra and corresponding fitting curves for (a) Fe−N−C-NMV, (b) Fe−N−C-SMV, and (c) Fe−N−C-MV; wavelet transforms of Fe K-edge EXAFS of (d) Fe−N−C-NMV, (e) Fe−N−C-SMV, and (f) Fe−N−C-MV; comparisons between the experimental K-edge XANES spectra and the theoretical spectra based on the corresponding optimized structures for (g) Fe−N−C-NMV, (h) Fe−N−C-SMV, and (i) Fe−N−C-MV (insets: the corresponding optimized structures, in which the gray, blue, and red balls represent carbon, nitrogen, and iron atoms, respectively).