7 ms·
Single-catalyst water splitter produces clean-burning hydrogen 24/7
- sappwaste 11y agoDon't accidentally drop it in the ocean
- Amorymeltzer 11y ago>This bi-functional catalyst can split water continuously for more than a week with a steady input of just 1.5 volts of atomicity. That's an unprecedented water-splitting efficiency of 82 percent at room temperature.
- stephengillie 11y agoIt would free up more O2 and increase the amount of oxygen in the atmosphere. Eventually. What would that do to greenhouse gases and global warming?If we converted (for example) 1% of the ocean to hydrogen, oxygen, salts, etc. Would air pressure increase? Or would the atmosphere simply expand? Edit: Since everyone's confused about how I'd power it, I'd use solar power. Solar panels can easily output 1.5v today.
- ars 11y ago??? It's powered by electricity. Where are you getting that electricity from?
- stephengillie 11y agoThe sun.
- ars 11y agoIs this just a thought experiment? If not, why not use that sun-electricity for more useful things?
- stephengillie 11y ago. . . Yes, this is a thought experiment. Were you seriously concerned that I had a solution for rising ocean levels?
- ars 11y agoOK, in that case 1% of the ocean weighs 1.33×10^19 kilograms, the atmosphere weighs 5.1441×10^18 kilograms. If you actually did this you would increase the atmosphere to 10 times it's current size - and most of that would be oxygen, unlike the current mostly nitrogen. Most of which would probably escape to space. You'd have to find something to do with the hydrogen though, if you released it it would just recombine with the oxygen and make water again.
- Sapient 11y agoStoring excess power generated during the day at night?
- ars 11y agoI covered that in a different post, but hydrogen makes a very poor storage medium. The multiple conversions are also very inefficient.
- Semiapies 11y agoOnly if you had current hooked up to it.
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- JshWright 11y agoThis process still requires electricity to pass between the anode and cathode. It doesn't just magically split water. To address your hypothetical though... Both would happen. Air pressure is just the weight of the atmosphere above you. If you add more gas to the atmosphere, it would indeed get 'bigger', and would therefore weigh more, resulting in higher air pressure.
- stephengillie 11y agoYes, this process requires so little electricity that it can be powered by scrap solar panels. I've got 2 at home that provide 1.5v each. TFA hasn't provided other details, such as required amperage.
- ars 11y ago> Yes, this process requires so little electricity that it can be powered by scrap solar panels. What?? The amount of hydrogen released is equal to 82% of the electricity input. Why are you saying "so little electricity"? If you have "so little electricity" you also have "so little hydrogen".
- stephengillie 11y agoThe process, as described, used 1.5v. That can be produced by a common solar panel. Thus we can scale it. And spread it across a small amount of time. Did you and everyone think I was proposing to use gigawatts and electrolyse 1% of ocean water in a few seconds? O_o
- ars 11y agoYou can produce 100,000v by a common solar panel as well if you want. Voltage is completely irrelevant, what counts is energy. > Thus we can scale it. I don't follow. What does voltage have to do with anything? > Did you and everyone think I was proposing to use gigawatts and electrolyse 1% of ocean water in a few seconds? O_o Um, yes. Do you have the slightest idea how much energy it would take to electrolyze 1% of the ocean? I did some math for you: you need 1.752×10^26 joules. If you had a gigawatt available to you it would take 5,552,000,000 years.
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- stephengillie 11y agoThe device generates a lot of O2 as a "waste product" (obviously) so could this be a viable way to oxygenate an atmosphere? It's somewhat amazing that they can use such common metals for both catalysts. Also it's remarkable that only 1.5V is required for the operation. That's a common output voltage for solar panels. This design should be ripe for space travel applications. (I think the current solution produces electricity by recombining hydrogen and oxygen, so maybe this could also be an input for that?)
- masklinn 11y ago> The device generates a lot of O2 as a "waste product" (obviously) so could this be a viable way to oxygenate an atmosphere? Oxygenating atmospheres is easy (and obviously dangerous if you get high partial pressures), the issue is generally scrubbing CO2 out.
- stephengillie 11y agoIf you add enough oxygen, and keep adding oxygen, then eventually you'd get enough to breathe? Earth air is mostly a mixture of 72% nitrogen, 24% oxygen, 6% carbon dioxide, and other stuff. Could humans breathe if they were in an environment that was 78% carbon dioxide and 24% oxygen? (IANADoctor)
- Vendan 11y agoSurvive? No way. C02 concentration is between 0.036% and 0.041%. 1% would be uncomfortable and cause you to be drowsy. 7%~10% would lead to suffocation.
- masklinn 11y ago> If you add enough oxygen, and keep adding oxygen, then eventually you'd get enough to breathe? If you add enough oxygen and keep adding oxygen, eventually everything is on fire. > If you add enough oxygen, and keep adding oxygen, then eventually you'd get enough to breathe? Nope. As the sibling comment noted, around 1% CO2 will start making people uncomfortable and stuffy (the human body is not sensitive to lack of oxygen so much as excess of CO2, that's why e.g. nitrogen suicide is almost painless), and concentrations above 7% CO2 start being lethal regardless of oxygen presence. But CO2 has significant effects long before that, studies have shown decreased cognitive abilities starting at ~0.1% CO2.
- ams6110 11y agoWorth being clear that splitting water into hydrogen gas for use as a fuel, no matter how efficient, is still just another form of battery. If they really are achieving >80% efficiency that's getting up there with the best Li ion batteries, but hydrogen still presents a lot of handling and transport complexities for use as something like a motor vehicle fuel. Probably best used in large industrial scenarios, e.g. storing excess energy from solar or wind, and fueling gas turbine generators at night or low-wind periods.
- userbinator 11y agobut hydrogen still presents a lot of handling and transport complexities for use as something like a motor vehicle fuel With this efficiency, it could be feasible to just split the water at the point-of-use. I'm reminded of the "run your car on water/save fuel" scams which involved "HHO generators" - basically the same thing - located in the intake manifold and connected to a source of water and electricity from the car's electrical system. This time, it might actually do something interesting...
- knodi123 11y ago> With this efficiency, it could be feasible to just split the water at the point-of-use. Isn't it still a pretty slow process? Efficiency doesn't matter if it generates a trickle of H, and you need a large fixed volume. Splitting at point of use is silly anyway- why use power to split water into hydrogen you can use for a fuel cell to generate power, at the point of use?
- bane 11y agoThe engine could draw on a smallish stored reservoir of H2 for normal operation. That reservoir could then be continuously supplied with H2 from the process until it hits some pressure metric after which the system temporarily turns off until the pressure in the reservoir dips below some threshold.
- ars 11y ago
- endymi0n 11y agoPretty misleading article, mostly linkbait - the catalyst doesn't actually split the water, it's merely holding up to the electricity splitting the water better than other low-cost alternatives before. The principle and its disadvantages aren't different to William Nicholson in 1800. Electricity isn't for free. Hydrogen is hard to store and transport. Nothing new to see - move on.
- kbenson 11y ago> Hydrogen is hard to store and transport. If only there was a stable medium in which it could be transported, and an efficient way to extract it from that medium at a destination where it could be used... I think perhaps your focus is a little narrow.
- ksenzee 11y agoNo, water really isn't fuel storage. If you're at the destination where you want to use hydrogen for fuel, and you also have at your destination the electricity needed to split it, you can just use the electricity. No need to turn it into hydrogen and then burn the hydrogen.
- kbenson 11y agoExcept if you need a form of energy that you can distributed at a location, have abundant electricity and water at a specific point at that location, and don't have infrastructure to efficiently move electricity around. But yeah, transporting water itself probably isn't smart.
- Semiapies 11y agoExcept then you need 125% (at 80% efficiency) of that energy from another source handy in order to split the water electrically. It's not magic.
- ars 11y agoWhat's that medium? Methane? Edit: You could not possibly be talking about water, could you? How exactly were you planning on extracting the hydrogen from the water? No, there's no way you were talking about water, that would be far too stupid. So please tell me what medium you meant.
- DannoHung 11y agoI know this is another article about electrolysis catalysts, but this one actually seems pretty incredible. Does anyone know more about how far long this lab group is in their research and whether or not there are any commercialization partners at this stage? Have they run tests for longer than a week? Have they seen any degradation to the cathode or anode? Is there a reason to go beyond water electrolysis with the electrochemical tuning process in terms of energy storage?
- stephengillie 11y agoMy understanding (from reading the article) is that the single Li-ion battery lasted for a week. Considering that these are extremely common metals, I can't see why this wouldn't be viable, even with anode/cathode degradation.
- DannoHung 11y agoMaybe? The article was actually a little unclear on that. They may not have been able to run the experiment longer than a week. The only comparison they provide is the conventional catalyst which degraded significantly within 30 hours of operation.
- imglorp 11y agoMight this have value as a desalinator/purifier? Hydrolyze some dirty/salty water, then immediately recombine it in a fuel cell to produce some power and fresh water.
- canvia 11y agoI had an idea the other day of using electrolysis at the bottom of an extremely deep water filled shaft to generate gas bubbles that could be harnessed to turn turbines as they rose to the surface. Whether that could ever be more efficient than other power generation methods I have no idea. I guess the initial construction and ongoing maintenance requirements might make it not cost efficient. It was a fun idea to think about though!
- tinco 11y agoIt's an interesting idea. It seems a little crazy to go through the extremely energy intensive process of electrolysis just to create a gas, but you could recapture the gas and use it for something. There's got to be a catch though. I think it's going to be that gas is too light to effectively move a turbine so the amount generated will be really small (i.e. smaller than the electrolysis costs)
- stephengillie 11y agoYeah, we've got to expect the 2nd Law of Thermodynamics to come in and ruin the party. You could power the electrolysis from solar, but then you've got transmission loss on the wires. You're right the gases are too lightweight to push more than the lightest fan turbine. Even having the gases get separated, turn a turbine while floating up, get recombined into water, then be pulled down past another turbine by gravity, we might not get the full 1.5v back.
- pjc50 11y agoLook, bare hydrogen from electrolysis is not magic and not that useful. Hydrogen is a pain to store. What it is useful for is as input to the Sabatier reaction, where it can be combined with CO2 (if you can extract it from the atmosphere without expending too much energy) to produce methane. Which can be stored or turned futher into gasoline, jet fuel, etc. Or you could just use free Canadian propane: http://www.argusmedia.com/pages/NewsBody.aspx?id=1041736&menu=yes http://www.argusmedia.com/pages/NewsBody.aspx?id=1041736&men... or any of the natural gas being flared at the moment because it's too cheap.