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"Major Discovery" From MIT Primed to Unleash Solar Revolution

t r u t h o u t | "Major Discovery" From MIT Primed to Unleash Solar Revolution

more here (thanks Michael)

Scientists mimic essence of plants' energy storage system.

In a revolutionary leap that could transform solar power from a marginal, boutique alternative into a mainstream energy source, MIT researchers have overcome a major barrier to large-scale solar power: storing energy for use when the sun doesn't shine...

Requiring nothing but abundant, non-toxic natural materials, this discovery could unlock the most potent, carbon-free energy source of all: the sun. "This is the nirvana of what we've been talking about for years," said MIT's Daniel Nocera, the Henry Dreyfus Professor of Energy at MIT and senior author of a paper describing the work in the July 31 issue of Science. "Solar power has always been a limited, far-off solution. Now we can seriously think about solar power as unlimited and soon."

Inspired by the photosynthesis performed by plants, Nocera and Matthew Kanan, a postdoctoral fellow in Nocera's lab, have developed an unprecedented process that will allow the sun's energy to be used to split water into hydrogen and oxygen gases. Later, the oxygen and hydrogen may be recombined inside a fuel cell, creating carbon-free electricity to power your house or your electric car, day or night.

The key component in Nocera and Kanan's new process is a new catalyst that produces oxygen gas from water; another catalyst produces valuable hydrogen gas. The new catalyst consists of cobalt metal, phosphate and an electrode, placed in water. When electricity - whether from a photovoltaic cell, a wind turbine or any other source - runs through the electrode, the cobalt and phosphate form a thin film on the electrode, and oxygen gas is produced.

Combined with another catalyst, such as platinum, that can produce hydrogen gas from water, the system can duplicate the water splitting reaction that occurs during photosynthesis.

The new catalyst works at room temperature, in neutral pH water, and it's easy to set up, Nocera said. "That's why I know this is going to work. It's so easy to implement," he said.


 

Comments

hmmm... cobalt and platinum. May not be exactly inexpensive.

This looks pretty exciting - I know Dan Nocera, he's an extremely smart and credible guy. I've been out of town and didn't have access to his Science article.

Cobalt - not cheap, but not that bad - it is already the basis for LiCoO2 batteries. The platinum is the really expensive ingredient. The key to the possible importance of this discovery is whether both catalysts are deployed as surface species on high-surface-area supports, and whether they work for lots of catalytic cycles. Even platinum can be affordable if it is only needed as a monolayer on a support.

Hey Tim,

I was hoping you would comment. by monolayer on a support do you mean like a platinum plated honeycomb like they use on modern catalytic converters?

Also, do you think it is fair to call this a "solar revolution" when it really has nothing to do with solar? Sure the electricity can come from PV cells, but that was true of High Temperature Electrolysis. I don't remember anyone calling High Temperature Electrolysis a 'solar revolution'.

This reminds me a bit of that guy who was making hydrogen with salt water and a speaker. He conveniently left out how much electricity it took to power that speaker. Sure, it worked, but was it really any more efficient than any other way we have to generate hydrogen?

Lastly, isn't this just a slight variation on the electrolysis we've known about for over a hundred years?

If you're making hydrogen from sunlight, I'd call it a solar revolution - and it is nothing like anything we've ever been able to do with visible light. The ability to convert the UV part of the solar spectrum into hydrogen has been around for a long time, but that fails to make use of the most intense part of the spectrum. (Not surprisingly, chlorophyll exploits the most intense part of the solar spectrum.) Of course, since I haven't read the article, I'm not really sure what's involved here. The segment

...When electricity - whether from a photovoltaic cell, a wind turbine or any other source - runs through the electrode, the cobalt and phosphate form a thin film on the electrode, and oxygen gas is produced.
Combined with another catalyst, such as platinum, that can produce hydrogen gas from water, the system can duplicate the water splitting reaction that occurs during photosynthesis.

is not clear - is electricity needed to produce the catalyst continuously, or just as the catalyst is deactivated - requiring very little energy compared to the amount generated by water splitting.

is it not the case that phosphorus is being used instead of platinum as a catalyst, hence the affordability.

I do hope you'll read the article Tim.

Maybe I'm missing something here, but couldn't this just as easily be called a 'coal revolution', 'wind revolution', 'hydro-electric revolution', 'nuclear power revolution' or even 'hampster wheel revolution'?

I know I'm sounding snide here, but direct current electricity is the same no matter the source.

I'm sure you would agree the LED lights they are making now are a marvelous development for energy conservation, and will go a long way towards lowering our electrical demands, but would it be fair to call them a 'solar revolution' just because they can be powered by a PV cell?

I'm sure there's a logical fallacy involved here, I just don't know which one.

Norm, could you help me out?

Of course all electricity is the same. But there is a difference between primary and secondary energy sources. Hydrogen derived from fossil fuels does not help us reduce our dependence on fossil fuels. On the contrary, petroleum- or coal-derived hydrogen ultimately uses those fossil fuels even more rapidly since useful energy output is decreased for every energy conversion step we make. If a conversion step to electricity occurs between the fossil fuel form of energy and its conversion to hydrogen, we're no better off if we want to reduce fossil fuel consumption. (For obvious practical reasons, no one counts the solar input that went into forming fossil fuels millions of years ago.)

Anytime solar energy is the primary source of energy, whether used to power LEDs or used to generate hydrogen, I think it is fair to call that development part of a solar energy revolution whether or not the energy was converted to electrical energy as part of the process. If wind power is the primary source, it is likewise part of a revolution in renewable energy generation.

JH - As I read it, cobalt and phosphate were involved in the photocatalyst that generates oxygen, platinum is a component of another photocatalyst that generates hydrogen. (Mass balance is probably achieved by the additional formation of protons and hydroxide, respectively, in the two processes. If so, additional energy is obtained by harnessing the neutralization reaction in a galvanic cell.)

Syngas,

I reread my post and thought a little further clarification might be needed. The unclear part of the process described is in the use of electricity used to generate the cobalt/phosphate photocatalyst. Each active catalyst site may serve to assist in conversion of water to oxygen many times - using energy from photons - before some side reaction occurs to poison that catalyst site. If Nocera is using electricity to regenerate active sites, then one would not consider the use of electricity in the process to have been part of the solar to hydrogen conversion, but more like a penalty on the overall efficiency of the process. (Nasty side reactions poison catalysts!)

I'm disappointed Tim.

As you may know from previous discussions, I built and installed a solar water heating system for my home. About 75% of the heat for our water comes from solar energy (in the summer anyway).

If I were to apply the same logic Nocera is using, I could call a low-flow shower head a 'solar revolution'. Of course that is ridiculous. I use low-flow shower heads so my solar heated water goes further, and to conserve water, but I would use them even if I didn't have solar heated water.

I think Nocera is trying to market his discovery. To sex it up if you will.

I think Nocera is trying to market his discovery. To sex it up if you will.

I haven't read Nocera's paper, so I really can't argue his position, but I am sure he is being optimistic.

If his system works as I think he is implying I don't see the basis of your disappointment. He runs current through it to generate a catalyst that is needed to carry out the photochemical splitting of water to generate hydrogen and oxygen. I'm assuming that the energy content of the gases so generated is considerably greater than the electricity he must periodically use to regenerate the catalyst. In principle, that current could even be generated at the same location where the gases are made via a hydrogen/oxygen fuel cell, or even a thermal generated powered by burning the hydrogen. I don't know how well it really works, but it sounds great in principle!

Uh, I meant I was disappointed in your low threshold of what constitutes a 'solar revolution'.

'I'm assuming that the energy content of the gases so generated is considerably greater than the electricity he must periodically use to regenerate the catalyst.'

Whaaa? Now you're making Kanzius look sane.

Never mind disappointed, I'm shocked!

You could be right, but there are some reasons that I am not so cynical. Nocera is, as I've indicated, he is arguably the best Inorganic photochemist alive. He's not an assistant professor who needs to hype himself to establish his reputation, in fact he has more to lose with a bogus claim than he has to gain by hyping himself excessively. I strongly doubt that his funding is in any danger either.

Again, I haven't read Nocera's paper, and it possible that he is pleasing the MIT publicity office here - and is much more circumspect in his publication and in speaking to the scientific community.

From http://www.sciencemag.org/cgi/content/full/321/5889/620

[...]

English chemists first used electricity to split water more than 200 years ago. The reaction requires two separate catalytic steps. The first, the positively charged electrode, or anode, swipes electrons from hydrogen atoms in water molecules. The result is that protons (hydrogen atoms minus their electrons) break away from their oxygen atoms. The anode catalyst then grabs two oxygen atoms and welds them together to make O2. Meanwhile, the free protons drift through the solution to the negatively charged electrode, or cathode, where they hook up with electrons to make molecular hydrogen (H2).

The hard part is finding catalysts that can orchestrate this dance of electrons and protons. The anode, which links oxygens together, has been a particularly difficult challenge. Platinum works but is too expensive and rare to be viable on an industrial scale. "If we are going to use solar energy in a direct conversion process, we need to cover large areas," Turner says. "That makes a low-cost catalyst a must." Other metals and metal oxides can do the job but not at a neutral pH--another key to keeping costs down. In 2004, Nocera's team reported in the Journal of the American Chemical Society a cobalt-based catalyst that did the reverse reaction, catalyzing the production of water from O2, protons, and electrons. "That told us cobalt could manage multielectron and proton-coupled reactions," Nocera says.

Unfortunately, cobalt is useless as a standalone water-splitting anode because it dissolves in water. Nocera and his Ph.D. student Matthew Kanan knew they couldn't get over this hurdle. So they went around it instead. For their anode, they started with a stable electrode material known as indium tin oxide (ITO). They then placed their anode in a beaker of water, which they spiked with cobalt (Co2+) and potassium phosphate. When they flipped on the current, this created a positive charge in the ITO. Kanan and Nocera believe this initially pulls electrons from the Co2+, turning it first to Co3+, which pairs up with negatively charged phosphate ions and precipitates out of solution, forming a film of rocklike cobalt phosphate atop the ITO. Another electron is yanked from the Co3+ in the film to make Co4+, although the mechanism has not yet been nailed down. The film forms the critical water-splitting catalyst. As it does so, it swipes electrons from hydrogen atoms in water and then grabs hold of lone oxygen atoms and welds them together. In the process, the Co4+ returns to Co2+ and again dissolves into the water, and the cycle is repeated.

The catalyst isn't perfect. It still requires excess electricity to start the water-splitting reaction, energy that isn't recovered and stored in the fuel. And for now, the catalyst can accept only low levels of electrical current. Nocera says he's hopeful that both problems can be solved, and because the catalysts are so easy to make, he expects progress will be swift. Further work is also needed to reduce the cost of cathodes and to link the electrodes to solar cells to provide clean electricity. A final big push will be to see if the catalyst or others like it can operate in seawater. If so, future societies could use sunlight to generate hydrogen from seawater and then pipe it to large banks of fuel cells on shore that could convert it into electricity and fresh water, thereby using the sun and oceans to fill two of the world's greatest needs.

Wow - this is interesting although it's making my one- semester-of-chemistry brain hurt.
Syngas - I looked up Kanzius and I'm curious - is he considered insane? It also referenced Royal Rife who I heard about from someone else ages ago. Is he considered a quack or insane? I have no idea. Way outside my area.

I have to say that, judging from what I see in inwit's post, there is less here than I expected. Syngas has a point - the electricity could come from wind turbines as easily as it could come from solar cells.

Hey Jill,

I think Kanzius is both genius and insane (as was Da Vinci).

His invention is increadible, but some of the statements he makes when he gets in front of a camera leads me to believe he either thinks he has found an exception to the first law of thermodynamics (conservation of energy), or he thinks everyone else is stupid enough to believe he has (media loves this stuff).

Watch this and around 4:30 - 4:45, you'll hear him say we could use this to 'generate electricity'. Never mind it takes way more electricity to produce this hydrogen than you'll ever get back out of it.

Look up 'free energy', 'perpetual motion machine', or 'water fuel' on youtube, and you'll get hundreds of examples of scam artists, idiots, and conspiracy theorists claiming Big Oil is the only thing standing in the way of free fuel from water.

Even with one year of chemistry, you should remember that water is a very stable compound (my high school chemistry teacher used the word 'happy' in place of stable). It takes a tremendous amount of energy to get the hydrogen and oxygen to split due to their very strong polar bonding, so anyone claiming to get free energy from water is neglecting to tell you how much energy went into 'creating' that energy.

Remember, energy cannot be created or destroyed.

Tim,

It appears your OCD has gone into remission ;)

If you get a chance to read the report, I'd love to find out if Nocera's development is more effiecient than other methods of producting hydrogen.

Also, while it's remarkable that he can make oxygen with this process, how is that useful to us? I must admit my lack of understanding when it comes to fuel cells, but I thought they just used the oxygen in the air to oxidize the hydrogen. Would pure oxygen be better? Might it be more dangerous (BOOM!)

sorry for the typos :(

Syngas -- overcoming the stability of water ("cracking" it) has indeed been the biggest inefficiency in getting H2 and O2 from H2O, but that's what the catalysts are for (i.e., reducing the "activation energy" hurdle one must overcome). No one is talking about messing with the 2nd law of thermo here.

The point is to siphon off some fraction of the electricity generated during the day and apply it to the (now more efficient) water-cracking problem... and then recombine the H2 and the O2 in some kind of controlled fashion during the night to keep generating electricity when the sun input is down.

It's exactly analogous to siphoning off some part of the solar-generated electricity (the stuff that's not instantly used) and storing it in a lithium rechargeable cell. The difference is: the lithium cells suffer from inefficiencies (expense, limited recharge cycles before you have to throw them away and buy new ones), as compared to the OVERWHELMINGLY less toxic process of cracking water using Co and Pt catalysts, which do not participate in the chemical reaction 2H20 --> 2H2 + O2.

It does remain to be seen (and I'm keenly interested) in how storage of H2 and O2 in proximity to each other could be carried out safely.

But no one is even remotely entertaining a notion of getting around the laws of the universe. The key is increasing efficiency and lowering the toxicity of the ENTIRE system. Eventually, after zillions of catalytic cycles, the Co and Pt impregnated electrodes would require replacement, I'm sure, but this beats the crap out of existing rechargeable technologies, for efficiency and expense.

Regarding "other processes" for generating hydrogen... the only other that I know of at the moment is the extraction of the stuff from natural gas wells. Useful to an extent, but not without its own hidden costs - primarily transport. Much better to generate it onsite, as long as it can be done safely... as there will be pure oxygen around too, which by itself is incredibly dangerous stuff.

But no one is even remotely entertaining a notion of getting around the laws of the universe.

I don't deign to have the knowledge of a physicist.

I do know that the universe does not follow our laws. We attempt to understand the universe vis-a-vis certain laws..

And all of us amateurs pretend that we understand, and yet we understand just enough to be dangerous.

Wow - this is interesting although it's making my one- semester-of-chemistry brain hurt

Jill, it should make most people's brain hurt. It's way outside their area too, but most people don't want to admit it. That's all.

And as to "certain laws".. Understand that we refer to "laws"...

Oh, well, I'm too tired and exhausted to explain. Perhaps there's someone here who could better explain this than me..

"A little learning is a dangerous thing; drink deep, or taste not the Pierian spring: there shallow draughts intoxicate the brain, and drinking largely sobers us again."

-Alexander Pope

Thanks Stephen,

I agree with your assesment entirely. This is an exciting development and one I hope will lead to more alternative energy choices down the road.

In no way did I mean to impugn Dr. Nocera's claim to have developed a more practical way to isolate hydrogen and oxygen. What I questioned was the use of the term 'solar revolution' in relation to his discovery.

If I understand his invention correctly, the power source can be any direct current producing process. His claim to 'mimick photosynthesis' without actually producing sugar, or any hydrocarbon seems a stretch to me.

As for violating thermodynamic laws, that was Tim. I think he has backed off of that statement, so I wont elaborate.

As for violating thermodynamic laws, that was Tim. I think he has backed off of that statement, so I wont elaborate.

Ah, we have Syngas, an expert in physics. He's also an expert in accounting, finance, and politics.

Thanks JoAnn ;-)

Thanks JoAnn ;-)

So you agree? You're an expert as concerns the "laws" of physics? Wow! What a wonderful man you must be!

Well I hate to brag, but I've been subscribing to Popular Science for quite some time, ya know ;-)

Yeah, Syngas (and sorry for the misattribution of the thermo comment) -- the "mimicking photosynthesis" stuff seems to me to be hype as well... a hook used to sell the story in the popular press.

The biochemical processes, as a whole, of course obey the same energy laws (which, JoAnn... do not seem to be "our" laws -- they appear to be the universe's... all we have done is codified them with language... they seem to exist and are implacable in a very fundamental sense, independent of our ability to "understand" them vis a vis the language of mathematics).

Regarding "explanation", various people have tried to popularize them in prose, but there's really no "better" way to describe any of this stuff without simply writing equations and saying "there it is".

...but back to the biological processes... they are fundamentally based on the same thermo laws, by necessity of course, but have to follow tortured pathways involving boatloads of protein machinery for catalysis (enzymes, in other words) - which is the only way us animals can burn sugar without catching on fire... and the only way the plants can turn CO2 and H2O into sugar without the tooth fairy waving a wand over it. It's all an incredibly huge number of baby steps, each with its own enzyme that lets it all happen. So of course it's a stretch to compare the organic with the inorganic... but if I understand the scientists correctly, I think they were just talking about photosynthesis as an "inspiration". Physically, none of these concepts are anything more revolutionary than what you get from inorganic chem and physics... so in that sense, it seems like a little imprecise hype has entered - just to sell the thing to a wider audience. Seems to happen all the time in science reporting.

Well I hate to brag, but I've been subscribing to Popular Science for quite some time, ya know ;-

LOl! Well, you're an asshole, but at least you have a sense of humor.

they appear to be the universe's

Uh uh.. and how, in your infinite wisdom, do you account for irregular galaxies. Which laws do they obey?

Oops.. screwed up on the italics and shit...

The "laws" of the universe are "implacable"?

Seems that Stephen Muth also reads Popular Mechanics.

By that, JoAnn, I merely meant that they do what they do - regardless of our attempts to understand and codify. When we manage to figure out relationships between the thingies, whatever they are, it always crops up in the maths. I'm saying anything particularly new or insightful... it's along the lines of the kinds of sentiments expressed by hard scientists, usually in response to laypeople trying to wrap their heads around general scientific concepts... or in response to the strong PoMo crowd, whose stance is that men fashion this stuff within their circles to maintain their hegemony or some other such nonsense. Why so snippy?

BTW, my background is in biochem with boatloads of QM, thermo, and a smidgeon of statistical mechanics. That's where I left off.

correction: I'm not saying anything particularly new...

...it's kind of a poor restatement of a sentiment Einstein made along the lines that the most surprising / remarkable thing about the universe was that it was understandable at all. das' all.

Thanks for the clarification Stephen. And I apologize for being so "snippy".

btw, I like that word, "snippy".. Not too many people use it. You must not be from the U.S.

I mostly grew up in Alaska, which is kind-of like not being from the US (at least back then). I'm now also Canadian, Mexican and British, by insertion... and plan on leaving the country soon. I'd like to know what it's like to live under a remotely democratic rule sometime before I die.

Try to keep the chin up, in any event. Like I was saying before... the executive is only one branch of this sham of a government. There are other battles -- esp. the local ones -- where you can make a difference. The national elections are overrated... not much most of us can do about them, anyway.

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