Frequency electroreduction

Work at Coventry has shown the same switch from a two-electron to a one-electron pathway is occuring at higher insonation frequency in that the electroreduction of benzaldehyde at 800 kHz gives almost entirely the pinacol. A major benefit of the use of the higher frequency however is that there is little weight loss of the lead cathode compared to lower frequency (20 kHz) where it is substantially abraded away. 

Daujotis et al. [32] have described the use of electrochemical quartz microbalance for the quantitative studies on monolayer adsorption on working mercury electrodes. Mercury was deposited on Pt at negative potentials (—0.4 to —0.5 V versus AgjAgCljKClgat)- In order to avoid undesirable transformation of mercury into, for example, larger droplets, the thickness of mercury film could not exceed 20 nm. Then, the linear dependence of the frequency change on the added mass was achieved. Applicability of such an electrode for EQCM measurements has been demonstrated by performing electroreduction of Pb(II) and T1(I), as an example. 

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