Multifrequency Measurements for Double-Layer Studies

A capacitance transfer function based on the total double-layer capacitance can be 

This conceptual approach can be illustrated for a simple system involving adsorbed intermediates such as is described in Section 10.4. 

For a system without mass-transport dependence, if = f[V, 7), and, according to equation (10.3), the admittance is 

The transfer function i/V and the transfer function Cn/V can be neglected at this frequency. Thus the capacitance Cji may be considered to have its steady-state value. If Re can be neglected with respect to 1/ (/cuhfQi)/ the capacitance is obtained from the expression 

If the capacitance measured at high frequency tons using equation (14.44) is modulated at a lower frequency to, /(cuhf) will also be modulated at the frequency to. This approach can yield simultaneous measurement of Z to) and Qi(cu)/U(w). 

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