Metal oxide anodes consist of a layer of electrocatalytically active metal oxide coated on a titanium substrate by electroplating or the like. Unlike most metal oxides, these oxides are electrically conductive. The metal oxide anode was first applied to the chlor-alkali industry, and was later applied to other industries. In 1984, the United States began to use metal oxide anodes in cathodic protection designs in 1971 [2]. China has begun development and application in recent years. Because of its basic non-consumed characteristics, its application has become more and more extensive, and it has also been adopted by more and more anti-corrosion engineering designers.

MMO (Mixed Metal Oxide) tubular anodes are suitable for use in many environments such as soil, fresh water, salt water, and seawater. It is currently the most promising alternative to high-silicon cast iron anodes for cathodic protection of buried shallow-buried anodes and deep-well anodes in pipeline tanks, and it is light weight, long-life, and cost-effective.