MMO coatings are stated to be electrocatalytic towards the evolution of hydrogen, oxygen and chlorine, reactions that are very important in industrial electrochemistry. What does this mean?
To carry out an electrochemical reaction the potential of the electrode is changed either anodically or cathodically to support current flow and therefore generation of the required product. This change in potential is known as the overpotential, i.e., the difference between the thermodynamically reversible potential for the particular reaction and the operating potential.
Electrocatalysis may be broadly defined as the ability of an electrode surface to influence the rate of the electrode reaction. It involves the physical and/or chemical interaction of the surface with the ions or molecules at that surface. It is this interaction that lowers the energy required to drive the reaction, i.e., it reduces the overpotential required to sustain a practical current density. Hence, the use of electrocatalytic electrodes effectively reduces the cell voltage an process.