Corrosion rate of copper rotating-disk-electrode in simulated acid rain

✍ Scribed by S. Magaino

• Publisher: Elsevier Science
• Year: 1997
• Tongue: English
• Weight: 588 KB
• Volume: 42
• Category: Article
• ISSN: 0013-4686
• DOI: 10.1016/s0013-4686(96)00225-3

✦ Synopsis

The dependence of corrosion rate of a copper rotating disk electrode in (i) simulated acid rain solution (pH 3.5), (ii) a mixture solution of 5 x lo-' mol dm-' H2S04 and simulated acid rain (pH 2.1), and (iii) a mixture solution of 10d2 mol dm-3 HNOj and simulated acid rain (pH 2.1) has been investigated. In these experiments, the amount of copper dissolved into a test solution was analyzed by ICP-AES, and electrochemical impedance was measured. In the range of rotation speeds from 0 to 2500 r.p.m., the corrosion rate in simulated acid rain solution was found to decrease with increasing rotation speed. This decrease was more pronounced in 5 x 10e3 mol dmm3 H2S04 + simulated acid rain (pH = 2.1), and in lo-* mol dmm3 HNO, + simulated acid rain (pH = 2.1) at the rotation speeds above 100 r.p.m. Magnitude of the electrochemical impedance was correlated with corrosion rate, and relationship between corrosion potential and the reciprocal of the absolute impedance revealed a local anodic-polarization curve when the solution pH was 2.1. Decrease in corrosion rate with increasing rotation speed was found to result from anion-adsorption which is diffusion-controlled.