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Best anode materials for water-based hydrogen generator?

  1. Oct 8, 2018 #1
    I want also to build electrolysis based hydrogen generator or and water oxygenator/aerator. It's simple electrolysis device but requires special electrodes that are corrosion resistant or at least safe for human consumption. I seen that hydrogen bottles use platinum titanium electrodes. Platinum and gold have excellent resistance to corrosion but they are expensive. In this video I found good guide to electrolysis electrodes: https://www.youtube....h?v=Enf76lBNUIY

    Graphite is cheap although also tends to break down, discolor water and has low conductivity (graphene?). Other alternative is MMO electrode which is harder to find and expensive. Also I have considered sacrificial non toxic metal electrodes for example iron or pure magnesium rod since these minerals are even beneficial.
    There are cheap 16mm 99.99% magnesium rods on Ebay but since there are many scammers I might get instead magnesium rod with aluminum or other toxic metals. Any way to test purity?
    Titanium without platinum might be also good option but I'm not sure, titanium dioxide is anyway used in food as white pigment.

    Corrosion resistant anode would be better since I also have idea of building dual purpose device which could be used for aeration of roots in hydroponics like here:
     
  2. jcsd
  3. Oct 8, 2018 #2

    anorlunda

    Staff: Mentor

    If the plates are just plated with the expensive material, then the cost is not so bad.
     
  4. Oct 10, 2018 #3
    Well there are titanium platinum anodes on Ebay but can't sure they fake, without platinum coating. Platinum is even more expensive than gold so price supposed to be high. What would using just pure titanium anode?
     
  5. Oct 10, 2018 #4

    anorlunda

    Staff: Mentor

    Platinum plating is 0.5 up to 5 microns thick.
    Therefore you need 0.0005 cm3 of platinum per 1 cm2 of anode surface area.
    The density of platinum is about 21 g/cm3.
    So you need 0.0105 g of platinum, or 0.0004 ounces per cm2.
    The cost of platinum or gold (in round numbers) is $1000/ounce.
    Therefore a 1cm2 anode needs 4 to 40 cents worth of platinum, depending on the thickness.

    If you google platinum plating you can find numerous ways and places that do it as a service.

    I'm sure your electrodes will cost more than $0.40 each to make. But the cost of the plating material should not be the dominant cost.
     
  6. Oct 13, 2018 #5
    Thanks. For comprehensiveanswer :) Is gold as as platinum coating? I actually do happen to have old CPU that has like 2x2cm gold coated sufrace. I want to try magnesium rod 99.99% as anode but there is no way to know if there isn't alluminum without special test.
     
  7. Oct 13, 2018 #6

    anorlunda

    Staff: Mentor

    It's time for you to get serious. What are the required properties of your electrodes to make an effective electrolysis generator? If you don't know the requirements, all metals are candidates. What does https://en.wikipedia.org/wiki/Electrolysis_of_water tell you? Is it just the surface, or the whole mass of the electrode that matters?

    If you don't know how to specify the requirements, then it is time for some experiments. Many of us did electrolysis in the high school lab as an experiment. You could do that, and you could test several metals as the electrodes.
     
  8. Oct 15, 2018 #7
    Ok, looks like I'll just have to order from Ebay platinum coated titanium anode for versatile use and test it's quality. Don't want to do trial and error experiments which could cause poisoning.
     
  9. Oct 21, 2018 #8
    Does anybody know how to make or where to get PEM membrane used to separate hydrogen and oxygen?
     
  10. Oct 21, 2018 #9

    anorlunda

    Staff: Mentor

    Google is your friend. I quickly found PEM membrane on EBAY, Amazon, and Alibaba.

    Please do your own research before posting questions here.
     
  11. Oct 28, 2018 #10
    Today almost anything can be bought online but PEM come at high cost. Maybe some batteries use them or other devices?
    I also think maybe to try using iron anode after all since I need it anyway as supplement. Any ideas where to find pure iron or at least without nasty chromium 6 or other toxic metals?
     
  12. Oct 28, 2018 #11

    anorlunda

    Staff: Mentor

    The OP question has been adequately answered. Now, the questions are begging to ramble.

    Thread closed.
     
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