Rotating disk electrode (RDE) is a hydrodynamic electrode used in a three-electrode system that allows the control and determination of the reactant transportation near the electrode surface and its effects on the electrode reaction mechanism and kinetics. These electrochemical studies investigate the reaction mechanisms related to redox chemistry among other phenomena. The most popular voltammetry methods involve sweeping the electrode potential from an initial value to a final value at a constant rate, this is called linear sweep voltammetry. When the potential is swept repeatedly back-and-forth between two extremes, the technique is called cyclic voltammetry. In addition, placing a concentric ring to the rotating disk electrode (RRDE) allows to collect species that are produced on the disk. Homogeneous bulk reactions of intermediate species produced at the disk can be studied by comparing experimental data to theoretical terms. Major applications for RRDE instruments include: fuel cells, hydrogen production, depollution, and electrochemical sensing.
In our laboratory we have an electrode rotator with an adjustable range from 50 to 10,000 rpm that can be used for RDE and RRDE experiments. The electrochemical cell has a volume of 150 ml, five round glass ports, and an integrated water jacket to control the electrolyte temperature. Standard glassy carbon and gold electrodes with a diameter of 5.0 mm are available as working electrodes. The system is connected to a SP-300 potentiostat.
Rotating Disk Electrode (RDE) is an excellent technique for high-precision measurements of the catalyst's electrochemical properties (kinetics, diffusion constant, etc.). It is useful for high throughput catalyst screening, e.g., a series of bimetallic catalysts with different compositions. On the other hand, it is not a good indication of the actual performance of the catalyst in the real systems, as the reaction conditions are significantly different. The Rotating Ring Disk Electrode (RRDE) can be used for the reduction of the formatted species on the working electrode, which can help to uncover further information about the reaction mechanism.
The measurements on the half-cell Rotating Disk Electrode, with the complete equipment, several possible experimental configurations, and a fully equipped chemical lab.
Available working electrodes
Available reference electrodes
Available counter electrodes