Both the activity and selectivity of catalysts for the oxygen reduction reaction can be measured using a PAR Bi-STAT connected to a Rotating Ring-Disk Electrode (RRDE) half cell set-up.

Cyclic voltammetry tests of samples placed on the disk can give an indication of how a sample would perform in an actual fuel cell, or how much the potential will drop from the theoretical before the reaction rate (and current) increases.  For the RRDE experiments, the disk is surrounded by a platinum ring, which can be used to measure peroxide species that may form ans an undesired by product of the reaction.