Electrosorption Gibbs energy

No more than the slopes do they contain the electrosorption Gibbs energy. The surface pressure is experimentally accessible by Integration of the Gibbs equation dy = -Xjr d/i. The fact that some components are dubbed "charge determining" does not matter provided the sum Is taken over electroneutral components. This Is our choice, not that of thermodynamics which Is model-free. In practice this means that the r.h.s. of. for instance (3.12.4b( Is Integrated from the pristine surface at the p.z.c. to the final condition, determined by the final values of a°. cr and r. The surface pressure is a function of state, therefore... 

E is the standard (or formal) potential that involves the contribution originating from the standard Gibbs energy change of the adsorption. Usually it is selected in such a way that the rates of adsorption and desorption will be equal. In several cases the adsorption process is diffusion controlled. The rate of electrosorption processes occurring with some organic species can be limited by slow chemisorption. See also -> Zel dovich. 

Several important features of electrosorption follow from this simple equation. First, it becomes clear that the thermodynamics of electrosorption depends not only on the properties of the organic molecule and its interactions with the surface, but also on the properties of water. In other words, the Gibbs energy of electrosorption is the difference between the Gibbs energies of adsorption of RH and that of n water molecules ... 

It is easy to see that if we set n = 1 in Eq. (13.20), it reverts to the Langmuir isotherm. This should not be surprising, because no coverage-dependent Gibbs energy of electrosorption has been introduced in deriving Eq. (13.20). 

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