Breakdown of metal passivation layers

  1. Hi All

    I hope that someone where can help me out.

    Let's assume that we take a piece of Al foil and a Pt wire and put them into an ionic solution. We then apply a voltage difference of 2 V between the two. Al(+) and Pt(-). After a few seconds the Al electrode starts to corrode. Nothing new about that but can anyone tell me what happens before the corrosion starts? I assume that the aluminum oxide is being removed. I am interested in figuring out what voltage that is needed to remove the aluminum oxide. And the kinetics of it.

    If this can be described in a theoretical manner I will prefer that as I would like to compare different metal oxides at different voltages.

    Thanks

    Best regards
    Tom
     
  2. jcsd
  3. Borek

    Staff: Mentor

    Way too many unknown factors for a theoretical treatment, experiments are a way to go.
     
  4. Okay, thanks.

    Instead of testing every metal oxide there must be a way of finding those oxides that are most likely to be the best.

    Any idea of how to this?
     
  5. Borek

    Staff: Mentor

    In what sense?
     
  6. I want to find the best materials for passivating electrodes in ionic solutions.
     
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