Electrochemical reactions take place at the electrochemical interface, the region in which the properties change from those in the bulk of the electronic conductor (electrode) to those in the bulk of the ionic conductor (electrolyte). Not surprisingly, then, efficiency of energy conversion and energy storage processes are almost entirely determined by the richness of interfacial processes that control the rate of electron transfer and various types of interactions between the substrate and reactants, intermediates, and products of the reaction. The “interfacial bridge” between two bulk properties is built either by the formation of unique (near)surface atom arrangements (e.g. surface relaxation or reconstruction) and/or by significant differences in electrode composition close to the surface (e.g. segregation profile) and/or via substrate-adsorbates covalent and non-covalent forces and/or ordering of solvent and/or electrolyte molecules observed in the proximity of the surface (up to 10 nm). All of these processes are rather complex, requiring special arsenal of tools that are capable of resolving interfacial properties at atomic and molecular levels.

Despite establishing the structure-function relationships, i.e. correlations between the morphology, composition of the electrode/electrolyte and the physico-chemical properties of the interface such as activity, stability and selectivity, we are still not in a position to provide the fundamental knowledge that is required to control the interfacial processes.

This presentation will give an overview of our recent efforts in predetermining the properties of the electrochemical interface by influencing the delicate interplay between the covalent and non-covalent interactions at or near the electrode surface. Several examples of chemical modification of the interfaces are going to be presented, including the variation in oxygen reduction reaction (ORR) in alkaline solution with the nature of non-covalently adsorbed cation in the double layer, the ORR activity enhancement of PA fuel cell catalyst and hydrogen oxidation reaction selectivity enhancement on PEM fuel cell catalysts. Finally, we will discuss the control of interfacial electrochemical processes through the application of mono- and multi-layer graphene architectures.