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What is silanol and what could it be used for?

  1. Jan 24, 2006 #1

    Q_Goest

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    Interesting advancement in the creation of hydrogen from water. What is silanol and what are the uses?

    Read it here:
    http://pda.physorg.com/lofi-news-hydrogen-water-said_6137.html
    and here:
    http://news.uns.purdue.edu/UNS/html4ever/2005/050831.AbuOmar.hydrogen.html
     
  2. jcsd
  3. Jan 24, 2006 #2
    Isn't H2 used to synthesize the organosilanes in the first place? :uhh:
     
  4. Jan 24, 2006 #3

    Q_Goest

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    No idea, rach'. Fill me in, I'm not a chemist. I'm interested in the hydrogen so if it takes hydrogen to make this stuff, it seems a whole lot less interesting.
     
  5. Jan 24, 2006 #4

    ShawnD

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    Silane is like methane, but it has silicon instead of carbon.
    Silanol is silicon alcohols like Si-OH

    As rach said, you need hydrogen to make silane.
    http://en.wikipedia.org/wiki/Silane
     
  6. Jan 24, 2006 #5
    Edit: I'm wrong!

    I think excesss hydrogen is in fact produced:
    ................
    SiH4 + 3H20 -->SiH(OH)3 + 3H2

    With an extra mole of H2 for each mole of SiH4 (comes from the H2O).

    edit #2: egregious typo
     
    Last edited by a moderator: Jan 24, 2006
  7. Jan 24, 2006 #6
    Last edited by a moderator: Jan 24, 2006
  8. Jan 24, 2006 #7

    Q_Goest

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    Rach, would this reaction be
    SiH2 + 3H20 -->SiH(OH)3 + 2H2
    ? ? ?

    I assume this is in the presence of the catalyst rhenium, is that correct?

    The reaction he gives in equation 1 also gives a R subscript 4-x. What does that mean?

    Is SiH2 silane? Abu-Omar talks about organosilane, is there any difference?

    It sounds as if he's proposing a storage method as opposed to a source of hydrogen which is where I must have gotten confused. From the article Rash' posted:
    Some of the other articles I've read discuss this method of hydrogen generation on par with electrolyzing water and reforming methane to produce hydrogen, but those reactions are intended to produce hydrogen, not as a storage means. Regardless, it sounds as if he's proposing a method of storing 6% by weight hydrogen under ambient temperature and pressure which is extremely interesting to the hydrogen economy. That's about the break point we're looking for.

    If SiH2 is silane though, that could be particularly nasty since it ignites in the presence of air.
     
  9. Jan 24, 2006 #8

    ShawnD

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    The problem is that silane is SiH4, not SiH2. All 4 of those hydrogens come from HCl, which is made from Cl2 and H2.

    What must be remembered is that you can't get something for nothing. If it seems like the extra hydrogen is a net gain coming from water, it's because your starting materials (Si, H2, and Cl2) were made using a lot of energy, and all of that energy eventually traces back to power made using conventional means (oil, nuclear, wind, whatever). If this idea is being pitched as another free energy type idea, it's not impressive by a long shot. If it's an energy storage idea, it's basically just another design for a fuel cell, aka batteries.
     
  10. Jan 24, 2006 #9
    Sorry about that... fell asleep at the keyboard or something.
     
  11. Jan 24, 2006 #10
    It's none of these. It merely demonstrates a particular catalytic method to get hydrogen from water; it doesn't much of a purpose, that's why I've been using the word "hype" so much. Especially when the author gets really speculative and suggests catalysts could liberate H2 from hydrocarbons in landfills. :confused:

    Q - organosilanes are in general compounds with both C-H bonds and Si-H bonds, such as (CH3)3SiH.
     
  12. Jan 25, 2006 #11

    Q_Goest

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    Thanks for the feedback Rach and Shawn.

    Also, thanks for clarifying the reaction, Rach.

    Wow, I can't believe he's suggesting using silane as a reactant. Way too dangerous for practical purposes on fuel cell vehicles. The company I work for installed a silane distribution hub about 6 or 8 years ago and I remember hearing that even the tiniest leaks from such things as cylinder valves instantly ignited. Not good...

    Do you think there is any way of getting around the issue of using silane or other dangerous gasses? Do the byproducts of the reaction present any safety hazard?
     
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