fundamental frequency of 9.00MHz (SEIKO) and had a geomet-
ric area of 0.20 cm2. The platinum electrode was cleaned with
sulphonitric solution and washed with dilutes. Afterward, it was
submitted to an electrochemistry cleaner, which consisted of suc-
cessive platinum oxidation and reduction cycles in a solution
of H2SO4 0.10mol l
−1 until characteristic cyclic voltammograms
curves of the platinum in acid were obtained.
EQCM measurements were accomplished simultaneously with
potentiodynamic and potentiostatic studies. For potentiodynamic
measurements, the initial potential was 0.00V, where no reaction
occurs at the electrode, and the final potential was −1.00V. A scan
rate of 20.00mVs−1 was used. Potentiostatic measurements were
made by applying a potential jump from−0.10V (no reaction at the
electrode) to −0.90 or −1.00V. The systemwas polarized for 30 s at
these potentials.
EQCM measures were performed using a Quartz Crystal SEIKO
EG&G model QCA917 microbalance. This was coupled to a PAR
model 263A power supply. The system was managed using M270
software from EG&G EVEN. The frequency measures conversion in
mass variation was made with base in Sauerbrey’s equation (Eq.
(9)). A sensibility coefficient of 858.80gHz−1 was used.