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Researchers generate hydrogen more efficiently from water
- acd 4y agoSounds similar to photosynthesis. Light+Water is converted into chemical energy. Interesting that lights boost hydrogen conversion in a similar fashion.
- wrycoder 4y agoNature article: https://www.nature.com/articles/s41586-022-05296-7 https://www.nature.com/articles/s41586-022-05296-7
- wrycoder 4y agoFrom the article supplement: In typical electrolyzer stacks, it is difficult to trigger light-induced COM due to the limited penetration of light. Recently, Zhang et. al. developed a redox decoupled water splitting device which can facilitate the COM mechanism in electrolyzer stacks. It enables the decoupling of HER and OER from the electrodes to spatially separated catalyst bed reactions via a pair of redox mediators. Oxygen evolution for this redox decoupled water splitting device occurs at the oxygen evolution tank, which can be made of transparent material. This option of choosing transparent material for the construction of the oxygen evolution tank implies the possibility of actualizing our proposed COM in this redox decoupled water splitting device. Furthermore, the electrocatalyst powders can be directly dispersed in the electrolyte without the need to coat on a substrate. This can then enable the effective utilization of light by the catalyst, and the photon can then be used to effectively trigger COM. Thus, based on these considerations, the proposed COM can be actualized in this redox coupled water-splitting technology.
- abudabi123 4y agoThere isn't a way to harvest the light in sonoluminescence, yet. https://en.wikipedia.org/wiki/Sonoluminescence https://en.wikipedia.org/wiki/Sonoluminescence
- rjmunro 4y agoIt would be good if there was some sort of indication of how much more efficient the process is. Is it a 5% improvement or a 50% improvement?
- AtlasBarfed 4y agoWell, it's a typical hydrogen news story. So while there is a lot of potential in hydrogen, a LOT of legitimate and useful use cases, and likely some real fundamental science in the article, the hyping of hydrogen is a desperate astroturfing campaign by oil/gas/nuclear to stave off EVs and wind/solar/battery which is eating their lunch in raw economics. Thus the lack of real numbers intentional. Hydrogen production isn't efficient compared to grid transport and battery/hydro storage, because water is a very stable molecule and splitting it will fundamentally take a fair degree of energy and thermodynamic/heat loss/entropy.
- pitaj 4y agoI understand the oil/gas industry produces hydrogen from methane. But why would nuclear care whether their electricity is used for electrolysis or battery EVs?
- VBprogrammer 4y agoThere was recent news on this calling it purple hydrogen or something silly. We're so far away from having sufficient green (or green adjacent) hydrogen supply to cover existing industrial uses that it's pointless even considering it for transportation.
- PaulHoule 4y agoGen 4 Nuclear could use sulfur-iodine or other thermochemistry to make hydrogen directly rather than spinning a turbine and doing electrolysis.
- pfdietz 4y agoIf anything, cheap electrolysis is a deadly threat to nuclear. Green hydrogen solves the last remaining problems for a 100% renewable grid (the rare dark/calm periods and seasonal leveling.) Cheap electrolysers mean nuclear is defenseless against much lower LCoE renewables.
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- Maursault 4y agoSounds a little like the plot from Chain Reaction (1996).[1] [1] https://en.wikipedia.org/wiki/Chain_Reaction_(1996_film) https://en.wikipedia.org/wiki/Chain_Reaction_(1996_film)
- photochemsyn 4y agoTechnically this is about evolving oxygen gas from water more than it is about the hydrogen end of the electrocatalytic reaction. Since this is a cathode (2H+ + 2e- -> H2 gas) vs. anode process (2H2O -> 4H+ + 4e- + O2) linked up by a wire to close the circuit, you have two chemical processes to manage. The oxygen-evolving one tends to be slower, i.e. rate limiting. For an overview: https://sci-hub.se/10.1039/c9cs00607a https://sci-hub.se/10.1039/c9cs00607a Song, et al. (2020). "A review on fundamentals for designing oxygen evolution electrocatalysts." Chemical Society Reviews. >"Therefore, the OER is the key process that governs the overall efficiency of electrochemical water splitting. To date, IrO2 and RuO2 have been state-of-the-art OER catalysts. However, both of them are made of precious metals and the cost is high. Therefore, it is imperative to seek low-cost alternative materials that can effectively reduce the kinetic limitation of OER and improve the efficiency of water splitting." So, they discovered that the catalyst used at the OER end has some light-activation property, which is pretty interesting, i.e. they discovered a kind of photovoltaic electrocatalyst. Whether it will prove to be industrially useful is anyone's guess. There are similar systems but they're not very practical (i.e. they require high-energy UV): https://physicsworld.com/a/light-activated-catalysts-make-nearly-perfect-water-splitters/ https://physicsworld.com/a/light-activated-catalysts-make-ne... As far as hydrogen-from-water tech, again it has three plausible large-scale cleantech industrial uses: ammonia from atmospheric N2, reduction of iron ore to sponge iron, and methane (and plausibly jet fuel) production from atmospheric CO2.
- PaulHoule 4y agoHydrogen has numerous uses. Petroleum refineries produce and consume hydrogen in numerous places, if they find they are steam reforming they could use green hydrogen instead, together with storing waste Carbon dioxide to green operations. Even if we quit refining oil from the ground we will still be doing chemistry like petrochemisty with other feedstocks.
- photochemsyn 4y agoIf you can figure out how to get the carbon feedstock from the atmosphere at scale, why would anyone bother with refining a mixed muck coming out of the ground? What we call 'petrochemistry' today will be called 'aero-hydro-chemistry' tomorrow.
- srejk 4y agoThere are legitimate use cases for hydrogen. Trains are a good example - electrification of medium to long distances (through tough terrain) is prohibitively expensive, as is battery usage for the whole journey. Trains require a lot of energy to get started (where batteries work well), but then a relatively small trickle of power is needed: hydrogen fills this niche. Big companies are investing billions into this right now.
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- Vvector 4y agoMaybe we could power the trains along the rail, or in catenary above? Add a very small battery to power it maneuvering around the rail yard?
- Kuinox 4y agoHow do you restart the train after stopping in the middle of nowhere ?
- kobalsky 4y agohydrogen generators?
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- bryanlarsen 4y agoTrains are a silly use case for hydrogen. Electric trains have been used and viable for approximately 100 years. The only problem is how expensive it is to electrify thousands of miles of tracks. That problem is now gone, batteries can be used to bridge gaps in the catenary wires.
- PaulHoule 4y ago‘No ignition is needed’ is wrong. It doesn’t take much to ignite hydrogen but you do need a spark. You can always find a spark in an industrial environment so you can count on the Centaur blowing up in the Space Shuttle bay or the hydrogen bubble in a nuclear meltdown causing an over pressure event if not a consequential explosion.
- Proven 4y ago
- dheera 4y agoIs there any chemical way to store hydrogen in a car without pressurizing it? Driving around with a pressurized tank of combustible gas doesn't sound fun.
- stasmo 4y agoLiquid fuel can be created from carbon dioxide and hydrogen. https://www.nationalgeographic.com/science/article/carbon-engineering-liquid-fuel-carbon-capture-neutral-science https://www.nationalgeographic.com/science/article/carbon-en...
- uagenzlepe 4y agoIt can be stored as metal hydrides. Hydrogen atoms can penetrate he crystal lattice of certain metals to form a metal hydride, usually a very fine powder. These are stable at pressures a little higher than earth's normal atmospheric pressure.
- mappu 4y agoFraunhofer are doing this thing: https://en.wikipedia.org/wiki/Powerpaste https://en.wikipedia.org/wiki/Powerpaste
- pencilguin 4y agoWhat makes electrolysis expensive is a whole bunch of secondary details. Impurities in the water foul the catalyst, or steal power for side reactions that may contaminate the product or the water. The best catalysts are expensive metals that you would like not to erode and be carried away. After you get the hydrogen atoms separated from the oxygen, the oxygen atoms bond to become O2 molecules, releasing heat uselessly, and will later need to separated again (other oxygen, of course) when you burn the hydrogen, consuming much of the released energy; and likewise for hydrogen molecules. The recent story about using water vapor as the feedstock might signal a solution to the impurities and erosion problems that introduces new problems to solve before it can be used. Efficiency of the process is becoming unimportant as the cost of solar and wind-generated energy continues rapidly down, making other things like the cost of equipment and the volume of production more important. The frequent reports on improvements to electrolysis indicate not hype, but research cumulatively improving an important process, just as improvements in production techniques drove and still drive down the cost of solar panels.
- PaulHoule 4y agoAccording to Wikipedia existing electrolysis systems are between 70-100% efficient. It's not fundamentally difficult to do (when I was a kid I made a "rechargable bomb" that would fill a balloon with hydrogen+oxygen and blow it up) but if you are doing it at scale you are going to be very concerned about capital cost and energy efficiency so there is room for improvement.
- pencilguin 4y agoThe important number when using hydrogen to carry energy is the round-trip efficiency. It has been hard to improve the efficiency of the energy-releasing side. We are fortunate that the number's importance is declining.
- PaulHoule 4y agoI don’t think the main interest is energy storage today, I think it is to replace other sources of hydrogen in industrial processes. Hydrogen as a fuel to say cook food or run a power producing turbine competes with many other energy sources and carriers but for industrial purposes there is often no alternative or the alternative is carbon heavy. (E.g. carbon monoxide is used to reduce iron in a blast furnace, hydrogen is substitutable for CO for many metallurgical functions.)
- sitkack 4y ago> "This drop in performance, nobody has ever noticed it before, because no one has ever done the experiment in the dark," said Assoc. Prof. Xue. How many modern discoveries like this can be accounted for somewhat sloppy experimental procedure? Sometimes there is not enough chaos in science, just messing around can open up crazy avenues of research. Love it! Table top physics is still alive and kicking. We need more people doing more outlandish (seemingly) things.
- pencilguin 4y agoProbably at lots of other labs their equipment worked in the dark, and they didn't try adding light.
- xsmasher 4y ago>Aspartame was discovered in 1965 by James M. Schlatter, [...] He discovered its sweet taste when he licked his finger, which had become contaminated with aspartame, to lift up a piece of paper.
- cryptica 4y agoSo long as the energy which can be produced from the hydrogen is less than the energy which is required to extract it, these scientists are safe.
- lgats 4y ago> Food companies use hydrogen gas to turn unsaturated oils and fats into saturated ones, which give us margarine and butter. Hydrogen is not used in the production of butter > Long-touted as a sustainable fuel, hydrogen fuel produces no emissions as it burns upon reacting with oxygen—no ignition is needed, making it a cleaner and greener fuel source. It is also easier to store, making it more reliable than solar-powered batteries. no ignition is needed? Easier to store?
- idiotsecant 4y agohas to be intentional. It easy to be half wrong, if you're 100% wrong it's as hard as being 100% right!
- nl 4y agoHydrogen makes a great way to store excess energy produced by wind and/or solar farms too. Efficiency isn't even particularly important - in many cases farms can produce too much power for grids to absorb so you just convert it to hydrogen and use in those rare times you don't have solar or wind power for longer than batteries can absorb.
- jillesvangurp 4y agoActually, it's pretty inefficient as a storage solution. There are far better storage systems that loose far less energy. Efficiency is important if the input (energy) is not free. That's why hydrogen based transport is a non starter because it costs about 3-5x the amount of energy. The other problem with hydrogen is that both storing and transporting it are hard problems. A lot of it just boils off. It takes up a lot of space. Compressing it to 600bar takes up a lot of energy and requires some heavy duty equipment. Etc. Most hydrogen that is currently produced is used on site and not stored/transported.