Fig. 5: Mechanism investigation via EIS, Raman, and ATR-SEIRAS.

a Operando EIS curves collected at different potentials and the corresponding (Note: the red color represents the larger value while the blue color represents the smaller value). b Nyquist plots under 1 M KOH with and without 1 M methanol electrolyte for Ni3FeN-Ruburied. c Operando Raman spectroscopies of the Ni3FeN-Rusurface and Ni3FeN-Ruburied at different working potentials during the MOR process. d Operando ATR-SEIRAS spectra of the Ni3FeN-Ruburied under different potentials at 1 M KOH with 1 M methanol electrolyte. e Periodic electrochemical measurement over Ni3FeN-Ruburied.