Electrocatalytic reduction of hydrogen peroxide at Prussian blue modified electrode: An in situ Raman spectroelectrochemical study

► Electrocatalytic reactions at Prussian blue electrode have been studied. ► In situ Raman spectral features show actual redox state of electrode modifier. ► Relative content of two redox forms depends on hydrogen peroxide concentration. ► Electrocatalysis proceeds within Prussian blue layer, not at outer interface.