What exactly is exchange current density when it comes to electrocatalysts? Is it favorable in electrocatalysis?

The exchange current is the current at equilibrium, i.e. the rate at which oxidized and reduced species transfer electrons with the electrode. In other words, the exchange current density is the rate of reaction at the reversible potential (when the overpotential is zero by definition).

 

https://en.wikipedia.org/wiki/Tafel_equation

 

when it comes to electrocatalysts

 

Well if adding an electrocatalyst changes the reaction rate then logically adding/removing an electrocatalyst must change the exchange current density.

Edited March 16, 20169 yr by fiveworlds

So this means a higher one is more favourable?

So this means a higher one is more favourable?

 

No it isn't because there is no current at exchange current density. It is merely a description of a chemical reaction rates happening at equilibrium.