‘Artificial leaf’ successfully produces clean gas

From Techxplore

by University of Cambridge

'Artificial leaf' successfully produces clean gas

This ‘artificial leaf’ uses water, sunlight and carbon dioxide to produce a widely-used gas, inspired by the natural process by which plants use the energy from sunlight to turn carbon dioxide into food. Credit: Virgil Andrei

A widely-used gas that is currently produced from fossil fuels can instead be made by an ‘artificial leaf’ that uses only sunlight, carbon dioxide and water, and which could eventually be used to develop a sustainable liquid fuel alternative to petrol.

The carbon-neutral device sets a new benchmark in the field of solar fuels, after researchers at the University of Cambridge demonstrated that it can directly produce the gas—called syngas—in a sustainable and simple way.

Rather than running on fossil fuels, the artificial leaf is powered by sunlight, although it still works efficiently on cloudy and overcast days. And unlike the current industrial processes for producing syngas, the leaf does not release any additional carbon dioxide into the atmosphere. The results are reported in the journal Nature Materials.

Syngas is currently made from a mixture of hydrogen and carbon monoxide, and is used to produce a range of commodities, such as fuels, pharmaceuticals, plastics and fertilisers.

“You may not have heard of syngas itself but every day, you consume products that were created using it. Being able to produce it sustainably would be a critical step in closing the global carbon cycle and establishing a sustainable chemical and fuel industry,” said senior author Professor Erwin Reisner from Cambridge’s Department of Chemistry, who has spent seven years working towards this goal.

The device Reisner and his colleagues produced is inspired by photosynthesis—the natural process by which plants use the energy from sunlight to turn carbon dioxide into food.

'Artificial leaf' successfully produces clean gas

Credit: Virgil Andrei

On the artificial leaf, two light absorbers, similar to the molecules in plants that harvest sunlight, are combined with a catalyst made from the naturally abundant element cobalt.

When the device is immersed in water, one light absorber uses the catalyst to produce oxygen. The other carries out the chemical reaction that reduces carbon dioxide and water into carbon monoxide and hydrogen, forming the syngas mixture.

Full article here.

HT/Yooper

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82 thoughts on “‘Artificial leaf’ successfully produces clean gas

    • The original research, over a decade ago, points out the need to decentralize energy production; “Personalized Energy”.

      Decentralized energy production is a wonderful solution for developing countries seeking energy and potable water.

      • It’s also a great solution for “developed countries” who for some reason do not seem to be able keep the power grid on.

        As for this “breakthrough”, I’ll bet it takes 6h of sunlight to produce on tiny bubble of gas. Not exactly going to get me to work or keep the house warm.

      • “Personalized Energy”.

        Great idea!

        Not only bicycles but things like treadmills in Gyms.

        Just imagine the fitness of everyone when they have to use the tread mill for 15 mins for every hour to light up the office and keep the Wifi going etc.

        • It is a great idea. One of the projects I ran across in the early 1980s was a bicycle for dentists.

          The bicycle provided a mode of transportation to remote areas. Once on site and with the help of people to ride it in a stationary state, the bicycle generated sufficient RPM to power dental instruments including a dental drill.

          It was a great idea that’s never seen the light of day.

    • re: “My experience with these academic wonders is they are often not scalable.”

      Verily.

      That’s been the situation Dr. Mills has faced with his tech, getting the reaction rate high enough to produce “utility-scale” (quantities of) energy. The solution he found a few years back utilized ‘liquid electrodes’ and a sealed Hydrino reactor. The precursor electrodes made of Tungsten enabled the creation of the necessary “pinch-discharge” (as is used in fusion reactions) to kick-off the Hydrino-producing reaction in the presence of the catalyst and Hydrogen to create the (mis-named) SunCell ™ ‘effect’ being tested, but those Tunsten electrodes in use at the time lasted only a mere fraction of a second before they vaporized in that early concept-test device. Lab runs of hours are now accomplished using ‘liquid’ electrodes in place of those solid metal Tungsten electrodes.

  1. The question with these technologies is all about scale up and production costs.

    But usually, a breakthrough like this stimulates lots of others to seek out improvements or other technology platforms capable of better performance.

    It will be interesting to see how far the field has progressed by 2030.

    • It’ll probably be like all the fusion schemes – always 20 years in the future. I always tell people: if you think science is hard, you should try engineering. Reality is a tough master.

  2. Good Heavens, the “Artificial Leaf” process was coined in a MIT research project over a decade ago. The research was funded by a USA DOE grant.

    What’s Up with this?

    Hopefully this process will finally be implemented yet I hope Cambridge isn’t claiming it as a new discovery.

    • Source: https://www.cam.ac.uk/research/news/artificial-leaf-successfully-produces-clean-gas. <– the research is pay walled

      Excerpt:
      "A bold response to the world’s greatest challenge
      The University of Cambridge is building on its existing research and launching an ambitious new environment and climate change initiative. Cambridge Zero is not just about developing greener technologies. It will harness the full power of the University’s research and policy expertise, developing solutions that work for our lives, our society and our biosphere."

      What Is Cambridge Zero?
      https://www.zero.cam.ac.uk

    • One of the hallmarks of the new climate driven science is the seemingly endless rediscovery of observations that were made more than ten years ago. Often the old discovery originated in a different discipline and therefore it languished out of the spotlight until some confidence artist comes up with a global warming spin. It is always exceedingly doubtful that climate scientists will do anything with their rediscoveries that real scientists haven’t already explored, except milk richer sources of funds. The older I get the more I feel that saving science needs to include cutting the number of scientists by say, 90%. The universities have become degree factories without regard for the ideals of natural philosophy.

  3. “naturally abundant element cobalt”

    If it is abundant how come it costs $ 36,000 a ton? And that supply is regarded as a major check on the number of electric cars that can be built.

      • thats what I was thinking
        its not abundant or cheap
        and how muh did the setup leaf thing cost i wonder?
        you’d need a hell of a lot of them sitting where and maintained how?
        and containment and transfer?

    • It is naturally abundant on the plant Zercan in the Alpha Centauri solar system. All we got to do is figure how to get it here.

    • That “naturally abundant element cobalt” is back breakingly collected by poverty stricken children.

      Leaving us with that statement “naturally abundant element cobalt” as a strong hint towards the accuracy of their other claims.

      Claims that apparently invoke unicorns and fairies to produce industrial quantities of syngas.

  4. An “artificial leaf” is kinda like re-inventing the wheel, when this wheel had already been invented by nature hundreds of millions of years ago. Advice to UoC — just plant more trees.

    • And if you were around Karl Benz time when he patented Motorwagen, you’d suggest that this transportation means had already been invented by nature hundreds of millions of years ago; all we need just more horses?

      • no he wouldn’t … but you should continue to act like you don’t understand what he means … its a good look …

      • Dumb analogy. My point was, since you didn’t get it, was that what the researchers did was yet again another waste of time and public-supplied grant money.

        • Why it’s a waste of money, because you have decided apriori that artificial leaf can’t be made to work more efficiently than the natural one? Or are you skeptical of its purpose? I’d suggest that “Saving the Gaja” is only one of the possible applications, and we saw over and over again that as soon as new technology arises many compelling applications would pop up.

    • Ugh, Again.
      Trees plant themselves. No need to plant them in the wrong places.

      What we need now is an artificial leaf that produces artificial seeds to reproduce itself.

    • Try these: Triadica sebifera, the Chinese tallow, Chinese tallowtree, Florida aspen, chicken tree, gray popcorn tree, or candleberry tree, is a tree native to eastern Asia. It is native to eastern China, and Taiwan, and introduced to Japan in Edo period. The waxy coating of the seeds is used for candle and soap making. It is useful in the production of biodiesel because it is the third most productive vegetable oil producing crop in the world, after algae and oil palm. This species is documented as a noxious invader in the southern U.S.
      https://en.wikipedia.org/wiki/Triadica_sebifera

  5. To judge this development one needs info such as amount of syngas produced by the device per unit of time and per unit of solar flux. The article as it stands is simply useless hype.

    • Their SI (with the raw data) has a listing error. I have submitted a report. so once they
      fix the link you will have the data….. which you will never look at anyway.

      “The photoelectrochemical (PEC) production of syngas from water and CO2 represents an attractive technology towards a circular carbon economy. However, the high overpotential, low selectivity and cost of commonly employed catalysts pose challenges for this sustainable energy-conversion process. Here we demonstrate highly tunable PEC syngas production by integrating a cobalt porphyrin catalyst immobilized on carbon nanotubes with triple-cation mixed halide perovskite and BiVO4 photoabsorbers. Empirical data analysis is used to clarify the optimal electrode selectivity at low catalyst loadings. The perovskite photocathodes maintain selective aqueous CO2 reduction for one day at light intensities as low as 0.1 sun, which provides pathways to maximize daylight utilization by operating even under low solar irradiance. Under 1 sun irradiation, the perovskite–BiVO4 PEC tandems sustain bias-free syngas production coupled to water oxidation for three days. The devices present solar-to-H2 and solar-to-CO conversion efficiencies of 0.06 and 0.02%, respectively, and are able to operate as standalone artificial leaves in neutral pH solution.

      • The neutral pH solution sounds like a drawback.

        Nocera’s artificial leaf allows for waste water input with potable water output.

        However, it also requires PV and a fuel cell.

      • You presume too much, Mosher. And then you laughably run a cut-n-paste to highlight claimed 0.06% and 0.02% conversion efficiencies from a highly engineered yet exceedingly low efficiency process. Color this 30 years experience metallurgical R&D and process engineer exceedingly unimpressed.

        All marketing sizzle, but the real ‘product’ is mighty thin gruel.

      • I read it. Water electrolyzers producing hydrogen and oxygen typically operate at above 80% electrical efficiency run cold and as high as 92% if run hot. Run the numbers for us Mr. Mosher and tell us all whether a conventional solar panel system powering an electrolyzer would be more efficient than MIT’s device operating at an efficiency of 0.02% to 0.06% cold or hot.

  6. I’m working on an innovative idea for “clean” gas, using unicorn farts. I know, that sounds counter-intuitive.

  7. I’m the link to the referenced article is a link to the abstrac of the research paper. Says it only runs for 1 to 3 days. Doesn’t say why but my gas is the catalyst stops working.

    • the membranes holding the active enzymes start to break down and quit working. It took nature a looooong time to prefect the leaf.

      A simpler way to do the process is to harvest plants, sun dry them, and then feed them into a modified syngas process that produces carbon monoxide, hydrogen, and some waste heat that can produce electricity to help run the process.

      • Now there’s a promising solution to all that perceived troublesome excess of carbon dioxide: oodles of carbon monoxide to contain safely from public inhalation and hydrogen to compress into thick-walled high pressure vehicle tanks. I’d sigh in great relief but I wouldn’t care to inhale anywhere nearby this ample largesse. Besides didn’t German vehicles produce this gas mixture onboard from available wood in a heated unoxygenated gas generator for critical transport with existing internal combustion engines when their fossil fuel supply was choked off during WW II.

  8. At least from my experience, if a technology such as this one doesn’t make it to market within 10 or 12 years it never will. There is usually something wrong with either the science or the cost/benefit analysis. I guess we will just have to wait and see if this one makes it. :<)

      • With what etudiant said below, i.e., “…efficiency of the demonstrator is well below 1%”, it sounds like they’re a bit off on the cost/benefit to start with. So far I doubt they can even cover the cost of the H2O.

    • Political interference throws in a wildcard to allow for faster adoption depending on who has financial stakes in the venture and access to public funds. That’s where the science and cost benefit analysis errors are ignored.

    • re: ” if a technology such as this one doesn’t make it to market within 10 or 12 years”

      For how long now have we known the chemistry, the reaction rates?

      Measured in centuries …

  9. Let’s see if I understand this correctly:

    IF the process is truly “carbon neutral” as claimed, this is a process that uses energy (sunlight) and water to produce hydrogen and carbon monoxide which is then combusted with oxygen from the air to produce—you guessed it—energy and water.

    Carbon dioxide is asserted to be a mediating chemical (somewhat analogous to a catalyst) that is conserved in the total process path.

    The second law of thermodynamics say this will always be a no net gain process and it only makes practical sense if its net efficiency in converting sunlight to mechanical energy or electricity in the overall process will be significantly greater than that of solar cells. It will still suffer from being dependent on when sunlight is available and the “life” expectancy of the artificial leaf material versus that of PV semiconductors.

  10. Without reading the paper, I would also guess the water has to be exceedingly pure to expect it to run for sustained conversion.

    I would also guess that biodiesel from algae fed bioreactors, expensive as that is at around $27USD/gal, is still cheaper than anything this tech can achieve even at scale.

    Just rent-seeking research.

  11. This is NOT an “artificial leaf”. Leaves turn carbon dioxide (CO2) into carbohydrate, not carbon monoxide (CO) & hydrogen. Many industrial processes already produces huge amounts of CO that have to be flared for safety. This is not a route to artificial fuel production, this is stupidity.

  12. It takes a lot of energy to raise matter from a low state back up to a high state.

    Let me guess. One square acre of this ‘Artificial Leaf’ under perpetual sunlight would be required to yield one gallon’s worth of gasoline energy per day.

    This is another (NOT) perpetual motion machine.

  13. a catalyst made from the naturally abundant element cobalt

    “a catalyst made from cobalt, a naturally occurring metal, but one which occurs in recoverable concentrations only rarely, at least some of which is produced by enslaved child labour in toxic, hazardous mine environments, without protective clothing or safety equipment, in countries where workplace legislation is only a theoretical concept”

    They need reminding of this from time to time.

  14. The choice is simple; we can either EAT, or we can grow enough of these plants; but not both.

  15. The Process uses water! a limited natural resource and water can be very dangerous, I was told so by an environmental luvvie. According to the WHO 300,000 people die in the world each year by coming into contact with water.

    Where is Greta when you need her! If water gets in the air, global warming will be an existential crisis! the fizzics say so!

    If you ingest too much water you vital organs stop working, and if it gets in your lungs then its “Goodnight Vienna”.

  16. So this device produces Hydrogen, Oxygen and Carbon Monoxide? In the same chamber? What could possibly go wrong when you mix Oxygen and Hydrogen? – “Oh, the humanity…” comes to mind.

  17. It appears this is just a type of new fangled solar water/CO2 ‘fool’ cell splitter to get the H required to bond with the CO to make the syngas after venting the oxygen which would be the feedstock to process up to liquid fuels in a later phase. Using the ‘cheap’ cobalt instead of platinum or silver for catalyst. Like the low tech solar panel, it would only really operate at any efficiency for about 4-5 hour either side of noon. Assuming this ‘leaf’ is more efficient than a hamster.

    If you added base load electricity to this 24/7, then it would at least operate at the peak efficiency it was designed for at noon. Of course, once could just use the electricity directly instead of making the gas. But if there was no fossil fuels, say you were on Mars, then this just might be the ticket. Assuming you needed to manufacture something like rocket fuel and wanted some oxygen for a side and also had electricity.

    Don’t get me wrong, I think in 100-200 years, the world will still be running on liquid high energy density carbon fuels. But it will be synthetic fuels. Until the star trek phaser tech or something similar is invented in the future, we are going to continue to use high density carbon liquid fuels for many things like air travel and ship transport and manufacture other commodities like pharmaceuticals, plastics and fertilizers.

    Obtaining the CO2 isn’t that difficult, even from direct air capture and the next phase of oil sand research is just taking the hydrogen out of the ground in-situ while leaving the CO2 and sand in the ground. Assuming we will have to develop the next generation of nuclear power/electricity, there will be plenty of electrons and thermal heat to utilize, and we can have all the carbon liquid fuels we will ever need. And if/when the oil sands are depleted in 200 years for hydrogen, then we can crack water for the hydrogen. What we really need is some type of cheap and safe atomic power that guarantees we have abundant electricity forever. Making affordable synthetic fuel (cheaper than oil in 100 years) will be the least of our problems as long as we commit to making some type of atomic energy our priority. And we should also drop the dread around CO2 being such a threat to the good Earth, because after all, it really is the magic molecule of life.

    • “The perovskite photocathodes maintain selective aqueous CO2 reduction for one day at light intensities as low as 0.1 sun, which provides pathways to maximize daylight utilization by operating even under low solar irradiance. “

  18. Too bad that there is not a cheaper, simpler, renewable and more natural source of methane fuel that doesn’t depend on scarse heavy metal and expensive manufacturing…

  19. The hype cycle is a graphical representation of the life cycle stages a technology goes through from conception to maturity and widespread adoption. The hype cycle is a branded tool created by Gartner, an information technology (IT) research and consultancy company.
    There are five key phases in a technology’s life cycle.
    Innovation Trigger: A potential technology breakthrough kicks things off. Early proof-of-concept stories and media interest trigger significant publicity. Often no usable products exist and commercial viability is unproven.
    Peak of Inflated Expectations: Early publicity produces a number of success stories — often accompanied by scores of failures. Some companies take action; many do not.
    Trough of Disillusionment: Interest wanes as experiments and implementations fail to deliver. Producers of the technology shake out or fail. Investments continue only if the surviving providers improve their products to the satisfaction of early adopters.
    Slope of Enlightenment: More instances of how the technology can benefit the enterprise start to crystallize and become more widely understood. Second- and third-generation products appear from technology providers. More enterprises fund pilots; conservative companies remain cautious.
    Plateau of Productivity: Mainstream adoption starts to take off. Criteria for assessing provider viability are more clearly defined. The technology’s broad market applicability and relevance are clearly paying off.

    Many technologies fail to emerge from the trough of disillusionment.

    • They conveniently left out what goes into manufacturing the device. No, it’s not carbon neutral. Construction counts – as they found out with wind turbines.

  20. When I read about this the other day in the Engineer magazine on line, my mind was transported to a scene from the Black Adder series.
    It’s the one where Percy announces he has perfected a way of making gold, and presents Black adder with his triumphant achievement. Black Adder corrects Percy’s observations and reflects the reality, i.e. Percy has produced a splat of green.

  21. Humanity needs hundreds of watt-hours of energy each day per person just for cooking, food preparation and storage, Add to this the energy needed for provisioning potable water and waste handling. Then there is heating and cooling. While advances like this one are interesting, they are far more of academic interest than of practical use on the scale necessary.

    Other technologies are afoot, like: https://brilliantlightpower.com/news/

  22. Making Syngas with high temperature and fuel with Fisher-Tropsch is pretty standard chemical engineering fare, used by Germany in WW2 and South Africa for many years. Depending on scale, it can be competitive with bio-diesel, and grain ethanol fuels. Using sunlight as the heat source limits this to low fuel production rates for the real estate used.

  23. Our energy infrastructure is not a given but a work in progress. It has evolved from animal power, windmills, and watermills, whale oil, to hydro, fossil fuels, and nuclear – and it will continue to evolve; and that evolution will be driven by the market for energy where new ideas and technologies will compete and market forces, not fear mongering activism, will determine winners and losers.

  24. None of the epic inventions of the late 19th and 20th century came from academia eg light bulb, automobile, radio, TV, phonograph, transitor, intergrated circuit….. I don’t expect any now. The drive in academia is to write a paper not to invent something commercializable

    • re: “None of the epic inventions of the late 19th and 20th century came from academia eg light bulb, automobile, radio, TV, phonograph, transitor, intergrated circuit….. I don’t expect any now. The drive in academia is to write a paper not to invent something commercializable”

      Add to that the Hydrino, and the (I contend the misnamed) SunCell ™.

      ristvan, are you reading this? Caveat to others as well …

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