Bridging the two ends: Designing materials to bridge electronic conductivity and catalytic activity in an electrochemical energy converter

Abstract The normal operation of an electrochemical converter involving electrocatalytic processes is the simultaneous combination of electrical conductivity (seen as electricity) and catalytic activity involving the same material so-called an “electrode.” Specifically, since the catalytic reactions need an electron transfer between the solid catalyst and the electrolyte either a liquid solution or polymer/ceramic capable of ionic conduction, the electrochemical kinetics depends on the catalyst and the electrolyte, i.e., the interface between them. This means that the nature of the electrocatalyst surface is determining. To reach high thresholds of performance, it is thus highly desired that those electrode materials bridge the two ends of “excellent electronic conductivity” and “outstanding catalytic activity.” In this chapter, we broadly examine how the nature of the utilized metal-based materials of metal, hydroxide, oxide, or oxyhydroxide to design electrodes impacts the energy conversion efficiency.