Tailoring of electrocatalyst interactions at interfacial level to benchmark the oxygen reduction reaction

The cathode process, oxygen reduction reaction (ORR), is crucial for producing green and reliable energy from the reorganization of chemical bonds in fuel cells. However, the application of ORR is limited due to its inefficiency, which can not only be attributed to the linearity of ORR intermediates binding energies (Eb*OOH, Eb*O, Eb*OH) on the catalyst’s active site (represented as *) but also to the serious influences of the watery environment on active sites. In an aqueous environment, catalyst interactions, including covalent, ionic, and van der Waals forces, at the interfacial level are critical in determining the catalytic activity and can considerably alter the kinetics and selectivity of ORR. Therefore, the interfacial confinement's unique properties can provide exciting new possibilities for designing molecular as well as material-based catalysts for ORR. Although several published reviews have focused on developments in interfacial engineering for electrocatalysis, not specifically for ORR, this domain still lacks an inclusive debate on the mechanism of interface structures during ORR. We highlighted the most recent employed strategies for interface structure construction and the role of interfacial interactions during ORR. Finally, the barriers and prospects for the construction of electrocatalysts based on such concepts as control of interfacial interactions, engineering, and technologies are also discussed.