Überspannungspotenzial

Überspannungspotenzial is a term used in electrochemistry and materials science to describe the difference in electrical potential that can drive a reaction, specifically one that involves the transfer of electrons. It is a measure of the driving force for oxidation or reduction processes. The term can be understood as the potential an electrochemical cell needs to overcome to initiate a desired reaction, particularly when it is not thermodynamically favored under standard conditions.

This concept is crucial in understanding phenomena like corrosion, where a potential difference between different parts of a metal surface can lead to the dissolution of the more electrochemically active region. Similarly, in electroplating and battery technology, controlling the Überspannungspotenzial is vital for achieving efficient and desired electrochemical transformations. It is often related to kinetic barriers that must be surmounted for electron transfer to occur at a significant rate. High Überspannungspotenzial implies a greater kinetic hurdle for the reaction to proceed. This potential is influenced by factors such as the electrode material, the electrolyte composition, temperature, and the presence of catalytic species.