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This paper aims to evaluate corrosion behavior of bare and PbO₂-coated stainless steel 316L, as prospective candidates for bipolar plates, in simulated proton exchange membrane fuel cell’s (PEMFC’s) environment under operating potentials.

A set of potentiodynamic, as well as potentiostatic, electrochemical experiments was carried out under both anodic and cathodic potentials. Gathered data were analyzed via fast Fourier transform algorithm for further investigation. X-ray diffraction analysis was also used for determining coating characteristics upon completion of electrochemical experiments.

Results revealed that bare SS316L is a better candidate for bipolar plate material under anodic potential, as it is cathodically protected. However, PbO₂-coated SS316L is favorable under cathodic potential, as bare specimen will suffer localized corrosion in the form of pitting.

It would be of interest if all the experiments are carried out in a PEMFC stack.

This research strives to promote the use of electrochemical noise measurement for practical corrosion monitoring of coated bipolar plates in fuel cells.

Improving the corrosion resistance of bipolar plates will expedite commercialization of PEMFCs, which in turn will translate into a substantial reduction in carbon footprint.

This research strives to promote the use of electrochemical noise measurement for practical corrosion monitoring of coated bipolar plates in fuel cells.

One way to analyze electrochemical signals is the wavelet transform, which transforms a signal into another representation whereby the signal information is presented in a multi‐scale manner. Using the inverse wavelet transform, it is also possible to split a signal into different components of different frequency intervals. The inverse wavelet transform is the concept underpinning this paper, the aim of which is to demonstrate that high‐frequency variations in current signals are as valuable as low‐frequency variations.

The set‐up for the experiments carried out consisted of two identical carbon steel working electrodes exposed to simulated concrete pore solution, sparged simultaneously with SO₂ and CO₂. The corresponding electrochemical current signal was studied using wavelet transform.

High‐frequency components of current signals are as informative as low‐frequency components. High‐frequency variations could show some electrochemical activities that are not obvious in the other parts.

This paper shows that high‐frequency variations can be taken into consideration along with low‐frequency variations, since both can provide complementary information about electrochemical activities.

The aim of this paper is to show that the use of energy distribution plot (EDP), usually employed by researchers to characterize the behavior of electrochemical signals in the framework of wavelet transform, could provide better understanding of the electrochemical behavior of a corroding surface if used along with the plot that is obtained from the standard deviation (SD) of partial signals (SDPS). A partial signal (PS) is obtained by limiting the inverse discrete wavelet transform to one crystal, and hence an SDPS is obtained by computing the SD of the corresponding PS.

The electrochemical current signals, obtained from two identical working electrodes (carbon steel electrodes) exposed to simulated concrete pore solution, sparged simultaneously with SO₂ and CO₂ were studied using wavelet transforms.

The results show two steps of passive oxide layer formation: formation of defective passive oxide layer, and strengthening of the passive oxide layer. The passive oxide layer breakdown where CO₂ as well as SO₂ are involved occurred at a pH of approximately 11. Both the EDP and SDPS plots should be used, simultaneously, to characterize the processes occurring on the surfaces of the exposed electrodes.

The results that were obtained can be regarded as the basis for better understanding and improvement of the noise analysis method.

This paper studies the corrosion behavior of carbon steel rebar before and after the simultaneous introduction of CO₂ and SO₂ gases in simulated pore solution, using EDP and SDPS plots obtained from the electrochemical current signals at different pH values.