Fig. 3
Operando SR-FTIR spectroscopy and XAFS measurements. a Operando SR-FTIR spectroscopy measurements for Ru-N-C during the acid OER. b The enlarged infrared signal at ~764 cm−1. All potentials are normalized referred RHE. c Operando EXAFS spectra and first-shell fitting curves for Ru-N-C at different applied voltages from the open circuit condition to 1.5 V during OER. d Operando XANES spectra for Ru-N-C during OER. Inset: magnified pre-edge XANES region. e Schematic illustration of the effect of oxygen adsorption on the electronic structure of Ru-N-C. f Electron density difference plot of the O-Ru1-N4. Yellow and light green contours represent the electron accumulation and deletion, respectively. The balls in gray, blue, red, white, and light green represent C, N, O, H, and Ru atoms, respectively. All potentials are normalized to RHE
