Ambipolar proton-electron conductivity

This is a good point at which to look a little closer at the ambipolar transport term that we have mentioned eartier in passing. The materials property of interest here is the protonic-electronic ambipolar conductivity term, which can be written in... 

We note that the molecular flux is proportional to the difference in hydrogen pressure (as in gas phase transport through a piorous membrane), whereas atomic transport has a square root dependence, and as such would behave similarly to ambipolar transport of protons and electrons limited by the conductivity of a minority concentration of protons. 

If one assumes proton (H ), oxide ion (0 ), conduction electron (e), and electron hole (h) as ionic and electronic charge carriers, hydrogen evolution at the permeating side will obey the ambipolar diffusion mechanism, expressed by Eq. (12.17) [36] ... 

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