(152a) Rotating Disk Electrode: From Fundamentals to Applications for Catalytic Activity Assessment of Porous Electrocatalysts

 From fundamentals to applications for catalytic activity assessment of porous electrocatalysts

The rotating disk and ring disk electrode techniques (RDE and RRDE, respectively), were first developed experimentally and analyzed theoretically by the Frumkin-school of electrochemistry, with seminal contributions by Frumkin, Levich, Dogonadze and others. Since its introduction in the late 1940s, RDE became one of the most important tools for recording and analyzing non-transient electrode polarization data and it has been employed countless of times in virtually every branch of electrochemical science and engineering such as electrosynthesis, fuel cells, batteries, corrosion, bioelectrochemistry and photoelectrochemistry. The main advantage of the RDE technique is the well-characterized and controlled mass transfer behaviour which allows, in many cases, a fairly easy separation and identification of mass transfer and intrinsic electrode kinetic (i.e., charge transfer) controlling effects. The goal of the lecture – intended for a wide audience of chemical engineers – is two-fold. One is to present an overview of the RDE technique starting from the fundamental mass transfer model represented by the Levich equation, extraction of electrode kinetic parameters based on the Koutecky-Levich analysis, and recent developments in the area of porous RDE. Second, a number of selected application examples will be discussed to show the versatility of the RDE method for assessment of the electrocatalytic activity. In this respect an important case will be the oxygen reduction reaction on a variety of electrodes, including porous catalyst layers relevant for fuel cells and batteries.