Tuning the electrochemical oxygen reduction reaction by tailoring the electrode, electrolyte and interface

Abstract

Hydrogen peroxide is one of the valuable chemical that can be widely applicable in medicine, industry and for environmental protection. Over the last years, many efforts have been devoted to synthesize the product via anthraquinone process or direct synthesis of using from H2 and O2 gases. However, expensive costs for operation and the safety issues have obstructed the large scale production. Alternatively, electrochemical conversion of molecular oxygen to on-site production of H2O2 provides a promising route. Understanding the electrochemical pathway of ORR is important for further enhancing the efficiency of the production. As the reaction occurs at the solid/liquid interface, engineering the electrode (e.g., geometric and electronic properties) and electrolytes (e.g., pH, solvents, and ionic species) have demonstrated to modulate selectivity and activity towards electrochemical synthesis of H2O2. In this study, we have tailored the electrode and electrolyte’s properties to correlate the outcome of enhanced selectivity and activity of H2O2 production. The changes in activity has been primarily attributed to the modulation of local structure of electrocatalyst while the components of the electrolyte such as alkali metal cations have demonstrated to play a crucial role in affecting the electrochemical pathway of H2O2 production. Realizing the important role of the components at the solid/liquid interface, rational design for high production of H2O2 in electrochemical pathway will be plausible.