Slashdot is powered by your submissions, so send in your scoop

 


Forgot your password?
Close
typodupeerror
×
Power Transportation Science

Highly Efficient Oxygen Catalyst Found 156

Posted by Soulskill from the fuel-for-the-cause dept.
eldavojohn writes "As detailed in the journal Science (abstract), a new compound composed of cobalt, iron and oxygen with other metals presents us with the most efficient way (found so far) of splitting oxygen atoms from water. These ten known compounds provide a reactivity rate that is at least an order of magnitude higher than what is currently known as the gold standard in such reactions. During their research, the team discovered that the reactivity is dependent on the configuration of the outermost electron of transition metal ions, which they exploited to develop this efficient catalyst. For rechargeable batteries and hydrogen fuel, this is exciting work from MIT's Jin Suntivich, Kevin J. May, Hubert A. Gasteiger, and Yang Shao-Horn, and the University of Texas's John B. Goodenough."
This discussion has been archived. No new comments can be posted.

Highly Efficient Oxygen Catalyst Found More

Highly Efficient Oxygen Catalyst Found

Comments Filter:

  • Looks like it was... (Score:1)

    by Anonymous Coward

    More than Goodenough.

  • Hydrogen (Score:5, Funny)

    by Anonymous Coward on Friday October 28, 2011 @09:23AM (#37868472)

    But I thought it was hydrogen we wanted from water. What good is being able to split off oxygen?

    • Damn, you beat me to it... :-(

    • Re: (Score:2, Funny)

      by sribe ( 304414 )

      But I thought it was hydrogen we wanted from water. What good is being able to split off oxygen?

      God, I hope you're being sarcastic...

      • Re: (Score:2, Redundant)

        by Dragonslicer ( 991472 )

        But I thought it was hydrogen we wanted from water. What good is being able to split off oxygen?

        God, I hope you're being sarcastic...

        Ditto

        • Re: (Score:1)

          by Anonymous Coward

          But I thought it was hydrogen we wanted from water. What good is being able to split off oxygen?

          God, I hope you're being sarcastic...

          Ditto

          But I thought it was hydrogen we wanted from water. What good is being able to split off oxygen?

          God, I hope you're being sarcastic...

          Ditto

          But I thought it was hydrogen we wanted from water. What good is being able to split off oxygen?

          God, I hope you're being sarcastic...

          Ditto

          - I was, and i think the poster was, too.

          God

    • Re:Hydrogen (Score:5, Funny)

      by Flyerman ( 1728812 ) on Friday October 28, 2011 @09:28AM (#37868556) Journal

      The thing about Water, is that if you pull out the Oxygen, you end up with Hydrogen. It's pretty cool how that happens, I know.

      • Re:Hydrogen (Score:5, Insightful)

        by m.ducharme ( 1082683 ) on Friday October 28, 2011 @09:44AM (#37868768)

        Unless of course the hydrogen binds to another chemical in the process of catalysing.

        • Re: (Score:3)

          by Raul654 ( 453029 )

          A catalyst is, by definition, not consumed in the catalyzed reaction. If they created a catalyst, then it will not bind to the hydrogen.

          • Re:Hydrogen (Score:5, Interesting)

            by m.ducharme ( 1082683 ) on Friday October 28, 2011 @10:29AM (#37869320)

            No, but other things may bind to the hydrogen, especially if the reaction occurs in open air. I thought about this after I posted, and went and checked the article. The article states that another catalyst is needed to separated out the hydrogen, indicating that it does bind to something other than the oxygen or the catalyst. The reason the article focusses on the oxygen-separating catalyst is that it is the bottle-neck, and not the hydrogen-separating catalyst.

      • Re: (Score:3, Informative)

        by Anonymous Coward

        The thing about this catalyst is, it works in alkaline solutions to produce water and oxygen. From the article (I know, I'm not supposed to actually read on /.) the reaction is 4OH- > O2 + 2 H2O + 4e-

    • Re: (Score:2)

      by tmosley ( 996283 )
      Presumably, it leaves behind hydrogen, as that is the only other component of water.

    • Just for a split second, I almost had an aneurysm. Thank you.

    • Re: (Score:1, Offtopic)

      by ejtttje ( 673126 )
      The troll is strong with this one ;)
    • The cathode reaction liberates H The anode reaction liberates O The two reactions need to happen in balance, so the slower one determines the rate of hydrolysis. Speed up the slow anode reaction and the whole thing goes bazingah.

    • Re: (Score:3)

      by necro81 ( 917438 )
      I'm not sure if you are being snarky or ignorant. Since you posted as anonymous coward, I will assume the worst. In any event, if you had bothered to read the article, you would have found this:

      Two catalysts are needed for [water electrolysis] — one that liberates the hydrogen atoms, and another for the oxygen atoms — but the oxygen reaction has been the limiting factor in such systems.

      Hydrogen aside, there are plenty of situations where it would be handy to have a ready source of oxygen. E

      • In reference to this article and summary if you trying to use this for fuel cells, getting hydrogen is the harder than getting oxygen which is abundant in the air. Most proposals I've seen to get enough hydrogen involve fossil fuels in some manner like using electricity from the grid (produced by a coal-firing plant) or cracking oil.

        • The electricity in the grid could also come from fission, wind or water. Especially wind+hydrogen is interesting, as hydrogen could function as the a buffer demand to soak up extra wind power in times of high winds.

    • Astronauts do not breathe hydrogen. Nor do submariners. Although why they are splitting water instead of carbon dioxide is what is baffling.

      • Re: (Score:2)

        by Genda ( 560240 )

        ...Although why they are splitting water instead of carbon dioxide is what is baffling.

        Because they have no place to put the endless tons of soot! You insensitive clod! You want to save the world? Invent a delicious high fiber cereal made from soot!

        • If carbon dioxide is split couldn't the carbon be compressed into coal and burned?

          •     Mmmm.. Open fire on a submarine.. or a spaceship.. That sounds lovely, as long as it's not the ship I'm on. Let me know how that works out for you.

                Compressing pure carbon may not have the desired results. You'd probably prefer coal or charcoal. You may impress your girlfriend with the compressed coal though.

            • Hmm I wasn't assuming this would take place on a submarine or spaceship, but I see your point there.

              •     I was just bringing that from the gp of your post.

                Astronauts do not breathe hydrogen. Nor do submariners.

                I'm sure party animals over at NASA could find something to do with hydrogen, carbon dust, and salt water (err, urine).

          • I'm sure there are some very useful things carbon can be turned into, other than coal. Imagine if you have solar panels/nuclear reactor providing energy, you split your water and CO2 and you get H2, O2 and C. I wonder just how many useful compounds are made up of those 3 elements.

  • Let's hope this works out better than the prospects for cold fusion.

    • Re: (Score:2, Insightful)

      by sbrown123 ( 229895 )

      Nope. It is a MIT press release of their typical "world changing" science that, for some reason, never sees the light of day. They make one of these astounding announcements every few months.

  • This device is perfect for those days when breathing is more important than drinking.

    • This device is perfect for those days when breathing is more important than drinking.

      Shao-Horn and her collaborators are now working with Nocera, integrating their catalyst with his artificial leaf to produce a self-contained system to generate hydrogen and oxygen when placed in an alkaline solution.

      If the reaction rate is good enough then getting water out of this is a matter of re-combining the H and O. I guess the open question is how the energy rates compare with RO.

      • Water + Energy (+ Catalyst) => Hydrogen + Oxygen (+ Catalyst)
        Hydrogen + Oxygen + Energy => Water + Energy

        Notice anything funny about that? I do... if the energies were just right (namely, less in than out), it'd be a perpetual motion machine.

        Hint: the energies aren't right, and it's not. You'll have to put more energy into it than you'll get back in a useful form. No catalyst will ever get you to the point where it takes less energy to split the water than you'd get back by recombining the H and O.

        • Hint: the energies aren't right, and it's not. You'll have to put more energy into it than you'll get back in a useful form. No catalyst will ever get you to the point where it takes less energy to split the water than you'd get back by recombining the H and O.

          That doesn't matter if you're trying to make drinking water. RO uses lots of energy too, both on the manufacture of the membranes and in the running of the plants.

    • If it works with salt water then you're not taking away drinking water...

      In fact by combining the Oxygen and Hydrogen seperated afterwards you can get safe drinking water from a non-safe source (such as the ocean)

  • Johnny B. GoodEnough

  • Catalyst Theory? (Score:3)

    by TheLink ( 130905 ) on Friday October 28, 2011 @09:32AM (#37868604) Journal
    Is there a good theory on how catalysts work, so that scientists can use it to actually design new catalysts rather than "try a whole bunch of stuff and hope one works better"?

    • Is there a good theory on how catalysts work...?

      Maybe John B has a Goodenough theory for you?

    • Yes. That was how they came up with this new catalyst.

    • Re:Catalyst Theory? (Score:5, Insightful)

      by Rostin ( 691447 ) on Friday October 28, 2011 @10:28AM (#37869298)
      I wouldn't consider myself a catalysis expert, but I do computational materials research to predict how atoms are arranged in the surfaces of alloys in order to understand how that affects their catalytic properties, so I do know a thing or three about it. The answer to your question is mostly no. There are good explanations of how catalysts work in many particular cases, but there is certainly no known straightforward way to design a catalyst to do arbitrarily specified chemistry.

      Think about this paper. I haven't read it yet, but from the abstract, it looks like it's about a group of researchers finding a single parameter that controls the activity of a particular, narrow class of materials for a particular reaction, and then exploiting that to create an optimal catalyst within this class of materials for that reaction. And for doing that, they were published in Science, which suggests that it's fairly clever, important, and original work. That should give you an idea about what the state of the art is in catalyst design.

      John Goodenough, by the way, is about 90 years old, still sharp as a tack, and a world expert in metal oxides (what the catalysts in this study were made out of). Back in the 70s, he "invented" (that's probably not the best word) the cathode material that's still being used in most commercial Li-ion batteries. I just say that to make the point that this research was probably not something that many people have the depth of understanding to do.

  • Some questions here. (Score:4, Interesting)

    by CFD339 ( 795926 ) <andrewp AT thenorth DOT com> on Friday October 28, 2011 @09:32AM (#37868606) Homepage Journal

    First, "at a rate 10 times the previous gold standard" is interesting, but meaningless. What is the actual rate, and how is it measured?

    Second, what is the cost and availability of the materials needed for the catalyst? Does this require some kind of unobtainium? The article is very vague here.

    Third, Is this something we can practically manufacture in any kind of real scale or are we talking microscopic results measurable only in the lab?

    • Re:Some questions here. (Score:5, Informative)

      by Arlet ( 29997 ) on Friday October 28, 2011 @09:35AM (#37868660)

      Second, what is the cost and availability of the materials needed for the catalyst? Does this require some kind of unobtainium? The article is very vague here.

      If I'm not mistaken, the materials are listed right there, in the abstract:

      Ba0.5Sr0.5Co0.8Fe0.2O3

      (Barium, Strontium, Cobalt and Iron, all abundant)

    • First, "at a rate 10 times the previous gold standard" is interesting, but meaningless.

      Rp = Reactions per time unit

      Rn = 10 (Rp)

      For Rp previous best rate, Rn new rate

      • Re: (Score:2)

        by Arlet ( 29997 )

        That still doesn't mean much. It would be nice to know what percentage of incoming energy from the light is actually converted into splitting water molecules.

        Does this compare favorably with a regular PV cell + electrolysis, for instance ?

      • First, "at a rate 10 times the previous gold standard" is interesting, but meaningless.

        Rp = Reactions per time unit

        Rn = 10 (Rp)

        For Rp previous best rate, Rn new rate

        Rp is just the benchmark of a standard method, not the previous best rate. So this isn't necessarily a 10x improvement over previous methods. Kinda like saying a standard lead-acid battery is the gold standard for batteries.

        • Kinda like saying a standard lead-acid battery is the gold standard for batteries.

          Well, it might be if we could just perfect Alchemy.

  • Oxygen Destroyer is what we'll need by the end of next year.

  • Cobalt-9. All the water on Earth gets transformed due to this. Then explodes in a highly combustible way.

  • How does this catalyst work? (Score:3)

    by JSBiff ( 87824 ) on Friday October 28, 2011 @10:25AM (#37869244) Journal

    Do you still run electricity through the water, but first you 'dope' the water with the catalyst, and the hydrogen/oxygen separation happens with same rate with less energy input/faster rate with same input?

    They mentioned something in the article about an "artificial leaf", so does that mean that you use sunlight as the energy input instead of electricity, and the sunlight drives the reaction with the catalyst?

    • Sorry, there is no way to reduce the amount of energy it takes to separate water into hydrogen and oxygen.

      This magic catalyst makes it go faster, but there is an absolute, defined energy required, and it would take an Act of God to modify this.

      If you want hydrogen fuel, great, but you have to put in as much energy as you get out later. Some forms of energy are more convenient than others, for instance "sunlight in desert" is less useful than, say a couple gallons of gasoline. Catalysts let you shuffle the

      • Wait, so you're saying that we were already at 100% efficiency? My understanding of it (which may be flawed), is that previously, with electrolysis, a lot of energy was being *wasted*? That is, it wasn't being used to split they water, but I dunno, generate waste heat or something?

        So, unless you are at 100% efficiency, you should be able to generate hydrogen with less energy if you can find a way to reduce the *wasted* part of the energy. There is, sure, an upper limit on how low the energy can go, since I

        • Re: (Score:2)

          by Belial6 ( 794905 )
          As a general rule of thumb, you can take any Slashdot post that calls out the laws of thermodynamics, and dismiss them as being written by someone who does not understand the laws of thermodynamics.

      • You are correct, there is a definitive minimum energy required to split up a water molecule and get out hydrogen and oxygen. This energy is the same as the potential energy that would be released if you burned the two gases together in an exothermic reaction, getting the water back. Typically though electrolysis uses much more energy than that, because there is a certain "activation energy" threshold that you have to reach before the reaction can occur. Without a catalyst you have to put in extra energy

    • The problem with electrolytic hydrogen is that electricity is expensive, not that the process is inefficient.

      • When your energy source fuel is 'free' like sunlight, wind or geothermal, then it quickly becomes 'cheap'.

        Hydrogen is only expensive because you have to pay for the fuel used to split the molecules. So now in hydrogen we have a way to actually store the energy of the sun/wind/earth for use at a later time and place. (Ok granted, oil technically does the same thing, but it takes a few million years to go from sun to fuel ;-) Hydrogen takes just seconds )
        • The source of energy might be free, but that doesn't mean the electricity generated from it is. It will remain to be seen if grid storage will become cost effective, and whether hydrogen storage will be cheaper than say, sodium/sulphur cells.

          • The source of energy might be free, but that doesn't mean the electricity generated from it is.

            Nothing is 'free'. But with solar, you only pay for the infrastructure...which as it happens you also pay for with gas. Solar doesn't have the fuel part of the which is the lions share of what you pay at the pump.

            • With solar, you pay for much more infrastructure. So much in fact, that by the time it's paid itself off, it's almost time to replace it.

        • The electricity costs whatever it is worth at the power line, regardless of the source.

      • Re: (Score:2)

        by Naffer ( 720686 )

        The problem with electrolytic hydrogen is that electricity is expensive, not that the process is inefficient.

        Well more accurately, it is both expensive and inefficient. The best catalysts (the ones which operate at the lowest overpotential) are often expensive iridium oxides. Catalysts made from more abundant elements tend to require a higher applied voltage, which reduces the efficiency of the system. That said, if you're burning natural gas to make electricity to split hydrogen from water, you're much better off steam reforming the methane directly to hydrogen in terms of efficiency.

  • This could be a source for water purification.

    I would think you would need some way to reduce the salt first tho.

    Perhaps large solar based plastic evaporator collectors. The condensate would flow into cells based on these catylsts producing clean water.

    The "leafs" they showed here a few weeks ago might be a better solution tho.

    • The condensate is already distilled water. Is that pure enough?

      • I'm not sure. Seems like it should be tho. just me not thinking.

        But desalination plants use active filtering I believe so I guess condensation wouldn't have a high enough volume.

  • Two hydrogens and one oxygen walk into a bar. The three get together and say, let's get wet!
    It's friday... cut me a break.

  • Gold standard? I thought Platinum was the pretty standard cat in such cases?

Slashdot Top Deals

The best defense against logic is ignorance.

Close