(510f) Mechanistic Insights into the Active Sites and Their Local Environments for Electrocatalytic Reduction Systems (Invited)

The electrocatalytic reduction of oxygen and carbon dioxide are pivotal processes in a number of future renewable energy strategies. Considerable progress has been made ovver the past decade in understanding reaction pathways and in the catalyst development. Herein we discuss the results from detailed potential-dependent ab initio molecular dynamics simulations together along with electroanalytical and experimental kinetic results for aqueous phase oxygen reduction over metal doped and metal-free nitrogen containing carbon electrocatalysts and CO₂ reduction over Bi metal substrates carried out in ionic liquid electrolytes. The results show that while the catalytic sites on the surface are important, the electrocatalytic activity and selectivity are ultimately controlled by the local nanoscale environments that form during reaction which involve not only the active surface site but the local electrolyte, solution and reactant. These environments mimic the analogous active sites in enzymes. The potential at which the reaction proceeds helps to self-assemble the local adlayer and electrolyte at the interface to provide enzyme-like cavities that can enable low potential energy paths for elementary proton and electron transfer steps as well as bond forming and breaking reaction pathways.