Which of the following accurately describes the function of hydroxyl ions in cathodic protection?

Hydroxyl ions play a crucial role in cathodic protection by inhibiting corrosion. In cathodic protection systems, especially those using sacrificial anodes or impressed current systems, hydroxyl ions are generated at the cathode due to the electrochemical reactions occurring there.

These hydroxyl ions increase the local pH level and create an alkaline environment, which is less conducive to corrosion. It is well established that many metallic materials corrode more slowly in alkaline conditions. Therefore, the presence of hydroxyl ions contributes to the reduction of corrosion rates on protected structures by altering the electrochemical conditions around the metal, thus enhancing the effectiveness of cathodic protection measures.

In contrast, decreasing pH would promote corrosion and increase the likelihood of metal dissolution, while increasing conductivity does not directly contribute to corrosion inhibition in this context. Promoting corrosion is the opposite of what hydroxyl ions do, as they actively work to prevent it. Thus, the role of hydroxyl ions in inhibiting corrosion is fundamental to understanding their function within cathodic protection systems.