Apart from DRIFTS, operando FTIR and Raman in the liquid phase are valuable vibrational spectroscopy techniques for revealing the active species, phases, and mechanisms. From a fundamental aspect, infrared spectroscopy reflects the change of dipole moment of molecules, while Raman corresponds to the variation in polarizability. Hence, Raman is more frequently employed than FTIR in the structural profiling of inorganic electrocatalysts due to the limitation of infrared energy. For instance, operando synchrotron Fourier transform infrared spectroscopies (SR-FTIR) were performed to uncover the atomic-level dynamics of active site evolution at the solid-liquid electrochemical interfaces associated with the reactive intermediates proceeding over a Ni1-NC SAC during ORR. As shown in O dissociation in ORR. Structural fingerprints and the metal-substrate interaction in carbon or oxide-supported SACs could be derived from operando Raman. The strong interaction between isolated Pd1 and CeO2