Electrochemistry corrosion monitoring

Because silver, gold and copper electrodes are easily activated for SERS by roughening by use of reduction-oxidation cycles, SERS has been widely applied in electrochemistry to monitor the adsorption, orientation, and reactions of molecules at those electrodes in-situ. Special cells for SERS spectroelectrochemistry have been manufactured from chemically resistant materials and with a working electrode accessible to the laser radiation. The versatility of such a cell has been demonstrated in electrochemical reactions of corrosive, moisture-sensitive materials such as oxyhalide electrolytes [4.299]. 

The application of this method of corrosion monitoring demands some knowledge of the electrochemistry of the material of construction in the corrodent. Further, it is only applicable in electrolyte solutions. 

Over the past decade, a revolution has occurred in the field of electrochemistry with the development of in situ and ex situ surface analysis techniques capable of resolving important phenomena on both microscopic and short time scales. These techniques should be adapted and utilized to characterize local physicochemical corrosion events in situ. In addition, in situ techniques should be extended to provide on-line monitoring of real-world systems where reliability often requires detecting the onset and progress of corrosion phenomena (e.g., pit depth and crack length) as a function of time. 

Sensor evaluations or fuel cell catalyst evaluations commonly use the oxygen reduction reaction and do not rec[uire the use of any external salt. The tip can use electrochemistry to detect products as they diffuse through porous membranes. Corrosion products may be able to undergo further electrochemical reactions, or could additionally benefit from using an ion-selective electrode as the tip. Many different applications can benefit from the ability to both control and monitor electrochemical reactions, with the added dimension of being able to provide spatial resolution thanks to the SECM. 

The measurement of the electrical potential between the piece of process equipment (or a probe of the same material) and a fixed reference electrode will provide information on the corrosion risks. The technique requires that the process fluid be conductive and the electrochemistry of the system well understood. Potential monitoring does not give a measure of the corrosion rate, but wfll indicate the... 

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