Abstract
The impedance of anodic dissolution of iron in nonaqueous formic acid was measured by use of a Lock-in amp coupled with a potentiostat in the high frequency range and Lissajous method in the lower one. In order to obtain the response of the steady-state, the impedance measurements were started after the polarization for 1.5hrs. The potentiodynamic current (i)-potential (E) curves of Fe/HCOOH-0.5mol HCOOK were influenced not only by the contents of water, but also the conditions of cathodic reduction. In the active dissolution range of Fe/HCOOH-0.5mol HCOOK, the two capacitive arcs were observed in the complex impedance (Z) plane. The presence of the capacitive arc in the lower frequency range would be ascribed to an adsorbed intermediate. As for the active range of Fe/HCOOH, the capacitive arc and the inductive one were observed in the Z plane.
