Corrosion protection of steel by catalyzed polypyrrole films

Platinum (Pt) was deposited potentiostatically on electrosynthesized polypyrrole coating over carbon steel rods to form catalyzed polypyrrole films. These films poised open circuit potential (OCP) of carbon steel in passive range for prolonged periods in contrast with polypyrrole films without catalyst, which initially hold OCP in the passive range but quickly becomes active. Consequently, the catalyzed polypyrrole films demonstrated sustained corrosion potential. Catalyzed film of about 33.3 μm thickness was able to provide 99.2% corrosion inhibition in 3.5% NaCl solution for prolonged durations.