Electro-reduction of diazonium salts on gold: Why do we observe multi-peaks?

Multi-peaks have been observed when reducing diazonium salts by cyclic voltammetry (CV). In order to explain that behavior, we studied the electrochemical properties of a fluorinated diazonium salt that exhibits a strongly passivating behavior on various micro-crystalline gold electrodes. We propose here that each sub-peak observed in CV corresponds to the reduction of the compound on a distinct crystallographic site.