Confinement effects for nano-electrocatalysts for oxygen reduction reaction

Oxygen reduction reaction (ORR) is one of the most technologically relevant reactions. It occurs at the interface of the electrocatalyst and electrolyte, where oxygen reacts with protons and electrons to produce water. Because the electro- catalyst is dispersed on a high surface area support, morphological confinement becomes critical, as it dictates proton and oxygen transport. Furthermore, confinement is induced by ionomer, ionic liquids (ILs), or molecular additives, and their impact on electrocatalyst reactivity and transport properties is currently not well understood. We present an overview of electrostatics and mass transport-induced confinement and zoom in into ILs and molecular additives and try to unravel how local confinement induced by them impacts ORR.

Automated summary

The oxygen reduction reaction (ORR) takes place at the interface of the electrocatalyst and electrolyte, with morphological confinement playing a critical role in determining the transport of protons and oxygen. The impact of ionomer, ionic liquids (ILs), and molecular additives on electrocatalyst reactivity and transport properties, induced by confinement, remains unclear. This study focuses on electrostatics and mass transport-induced confinement, zooming in on ILs and molecular additives to understand their impact on ORR.