Electrocatalysis, Fundamentals - Electron Transfer Process; Current-Potential Relationship; Volcano Plots

Introduction

Electrocatalysis is the science exploring the rates of electrochemical reactions as a function of the electrode surface properties. In these heterogeneous reactions, the electrode does not only accepts or supplies electrons (electron transfer), as in simple redox reactions, but affects the reaction rates interacting with reactants, intermediates, and reaction products, i.e., acts as a catalyst remaining unchanged upon its completion. The term electrocatalysis, an extension to electrochemistry of the term catalysis (Greek kata (down) and lyein (to let)), was apparently first used in 1934[1]. The beginning of intensive research in this area can be traced back to early 1960s in connection with the broadening fuel cell research. Many electrocatalytic reactions have great importance. These include hydrogen, oxygen, and chlorine evolution; oxygen reduction oxidation of small organic molecules suitable for energy conversion (methanol, ethanol, formic acid); and reactions of...