Nano-spike catalysts convert carbon dioxide directly into ethanol

October 18, 2016 8:26 AM

“Ethanol was a surprise -- it’s extremely difficult to go straight from carbon dioxide to ethanol with a single catalyst.”

Comes via the boffins over at Oak Ridge National Laboratory

The Full Publication: High-Selectivity Electrochemical Conversion of CO2 to Ethanol using a Copper Nanoparticle/N-Doped Graphene Electrode

posted by mrjohnmuller (36 comments total)

I woke up and saw this story, and thought to myself

"Don't worry about anything" 😬
posted by kuatto at 8:31 AM on October 18, 2016 [4 favorites]

Great now we can literally get drunk on air! Thanks, Science!
posted by Chrischris at 8:32 AM on October 18, 2016 [6 favorites]

So in theory we can limit climate change by getting more drunk?

Dammit, Chrischris beat me to it...
posted by dowcrag at 8:33 AM on October 18, 2016 [2 favorites]

Im actually pretty embarrassed to say I got so excited about the use of ethanol as a fuel, I completely forgot to get excited about the use of ethanol as a booze.
posted by mrjohnmuller at 8:37 AM on October 18, 2016 [35 favorites]

Repeat after me: Press releases from the discovering institution are never a good FPP.

This is a minor result and very preliminary, as evidenced by the journal it is in and the terrible conversion rate....

But on a more basic level ...... note the word catalyst. We still have to put vast amounts of electrical energy to go from a low energy system (CO2) to a higher energy molecule (Ethanol). All this does is speed the reaction up and stop us having to heat the system to get appreciable rates. This is merely a way of making the beginning of complicated-molecule feedstock for storage and chemical production..... if we have large amounts of energy, something that dozens of groups are doing better than these shmucks.

*.(and sigh, the comments above show such willful ignorance about topic that is vital to the world. some thing that mefi does exceptionally badly....) .
posted by lalochezia at 8:38 AM on October 18, 2016 [34 favorites]

In my experience metafilter is neither exceptionally nor wilfully ignorant, but I'm happy to ignore this thread anyway as I have cat gifs to watch
posted by doiheartwentyone at 8:46 AM on October 18, 2016 [10 favorites]

I mean...you're not wrong. But charging in with condescending accusations of ignorance seems like a sub optimal approach to making the case.
posted by Ipsifendus at 8:47 AM on October 18, 2016 [42 favorites]

I do wish the article had some indication of the level of energy input to effect this reaction. Still, even if this is just science fiction I enjoy reading about it and dreaming a bit. It's quantitatively a better use of my time than wandering down to the corner store for a lottery ticket, which is also a thing that has happened.
posted by meinvt at 8:57 AM on October 18, 2016 [4 favorites]

This isn't the informative post we'd like, as lalochezia said above. But can someone rescue it by jumping in with a backgrounder on nanospikes as catalysts, a context on whether this can be used for direct sequestration of carbon dioxide from air, and the efficiency of converting the electric input.

My internet's being rubbish (and I'm on my phone with a drip in my right hand), otherwise I'd provide some of these answers.
posted by ambrosen at 8:58 AM on October 18, 2016 [4 favorites]

I'm in camp lalochezia on this one [again]

TANSTAAFLL - There ain't no such thing as a free liquid lunch.
posted by Glomar response at 9:06 AM on October 18, 2016 [1 favorite]

So, like, we can save the world by brewing air booze inside active volcanoes? I have a cousin who designed plants that burn cellulose garbage, and make fuel alcohol. But doing something about CO2 pollution besides curbing it, is a great idea. *Hiccough!*
posted by Oyéah at 9:06 AM on October 18, 2016 [1 favorite]

We already have a huge global industry turning carbon dioxide to ethanol. which has been going for many thousands of years. I've done it myself (although I fear my deficit in the other direction is considerable). I don't know what the overall energy budget is per mole, but I do know we're nowhere near as smart as photosynthesis and Saccharomyces cerevisiae yet.

There is lots and lots and lots of interesting nano-thingy science going on, because we have quite recently learned to produce and refine the tools and materials to experiment at that scale. Most is highly experimental and most won't pan out to anything significant: until you see a well-worked out path to something important happening with good numbers and wide buy-in from a number of sources, hold any single report at the highest level of skepticism.

And a pox on university and research PR departments.
posted by Devonian at 9:11 AM on October 18, 2016 [4 favorites]

Well if nothing else we can say that the technology of writing press releases that tantalizingly hit as many facets of solutions to climate change and inadequate booze supplies as possible, is becoming very advanced.
posted by XMLicious at 9:12 AM on October 18, 2016 [3 favorites]

Isn't this what champagne has been doing for years?
posted by dances_with_sneetches at 9:13 AM on October 18, 2016

lalochezia: "All this does is speed the reaction up and stop us having to heat the system to get appreciable rates."

Isn't a catalyst meant to increase the rate of the chemical reaction? As per the article's abstract, this process can operate at standard temperature and pressure, which might be part of the excitement on this (admitedly) preliminary discovery.
_{(Although I may be wrong, I don't know nearly enough electrochemistry to follow the article)}
posted by andycyca at 9:15 AM on October 18, 2016 [1 favorite]

I'm in camp lalochezia

If it's schmucks vs. boffins, to be honest, I'm not in either camp.

And there can be little doubt that on an energy budget per mole for industrial ethanol, it's way ahead of fields of corn, and far more dispatchable.
posted by ambrosen at 9:17 AM on October 18, 2016 [2 favorites]

From the paper in the supplementary information they give a trace from a GC. The VAST MAJORITY of the gas phase above the "reaction" is CO2. They also cleverly hide their efficiency in Faradaic Efficiency in that for every bit of energy they put in 63% of it leads to the production of ethanol. No mention on the rate of mass conversion or batch size for running the reaction. Also no mention on the yeild of ethanol, only couched terms in faradaic Efficiency.

We already have a huge global industry turning carbon dioxide to ethanol.
Isn't this what champagne has been doing for years?

No that industry is turning Sugars into ethanol with a byproduct of CO2. Granted the sugars are usually from C)2 and sunlight but if we count that far back you're mostly made of CO2 as well.

Isn't a catalyst meant to increase the rate of the chemical reaction?

No a catalyst lowers the activation energy barrier for a reaction.

Come on people this is simple science 101 stuff here.

Read some primers before snarking.
posted by koolkat at 9:24 AM on October 18, 2016 [2 favorites]

Yeesh.

HomerBacksIntoTheHedge.gif
posted by orange ball at 9:33 AM on October 18, 2016 [8 favorites]

Glomar response: "TANSTAAFLL - There ain't no such thing as a free liquid lunch."

It doesn't have to be free and the article doesn't make the claim that it iis/would be. The paper states the catalyst isn't economically viable.

However a hypothetical room temperature and standard pressure process that converts electricity, water and atmospheric CO₂^* into ethanol would be a revolutionary godsend even if it was 20-30% efficient. Storage tank + water + solar cells + magic box = ability to create enough fuel over the course of a summer to heat a house over the winter.

Some problems: it's not clear, to me anyways (it's been a long time since college chemistry), how much water is used during the process or how clean that water has to be. And I'm doubting the current process would work with atmospheric CO₂ meaning you'd have to pair this with a CO₂ creator and not just setup anywhere you have a source of power and water.

^*I think they are using a concentrated CO₂ source for this catalyst
posted by Mitheral at 9:46 AM on October 18, 2016 [4 favorites]

Look I don't care about the science or the environment here, all I want to know is now that we have this knowledge how long until it shows up on late-night TV ads as a "magic stir bar" that you can use to turn your fresh can of Coke into a slightly-flat alco-soda by hooking it up to a battery

You know that it will happen, too
posted by caution live frogs at 10:00 AM on October 18, 2016 [3 favorites]

So, I'll be able to take this camping and still get drunk without lugging around a massive cooler full of beer?

That's a win, no matter how you slice it.

(Also, pedantry about the science is fine in a talk about science experiment, snobbery is not. Chill.)
posted by oddman at 10:07 AM on October 18, 2016 [6 favorites]

The good thing about the photosynthesis of CO2 to sugar is that you don't have to produce the energy to power it (if you're not growing your plants in a cupboard) and if my sketchy maths is correct you end up using two-thirds of the CO2 you put in if you go down the alcoholic fermentation path (six moles of CO2 = one mole of glucose, one mole of glucose = two moles of ethanol + two moles of CO2). I think 66 percent conversion efficiency is pretty good.

Plus, what are you going to do with the ethanol? If you're going to turn most of it back to energy, water and CO2, then it doesn't much matter CO2 comes out during the generation process. If three hundred years of industrial revolution and a hundred years of environmental awareness counts for anything, it's that you really do have to look at the whole system end-to-end to understand the way it affects other systems.

(Feel free to correct my 101 chemistry!)

Also, you don't have to do it (and experience suggests you shouldn't) by corn fields, or even alcoholic fermentation. Algae biofuels are still bubbling away, just for one example, and they are theoretically far better at turning CO2 and sunlight into useful fuels, including ethanol - but are also a really good example of how difficult it is to get a new technology to work in practice, for all sorts of technical, political and economic reasons. Any new nano-magic is going to have to swim in those waters too, before you get your household winter fuel or magic booze stick.

Look, i love new science with a burning passion. But i have seen so many high-spin, low-fibre PR stories turn into breathless press coverage - especially in the hot topics of energy conversion and storage - that I am automatically That Guy unless circumstances really dictate otherwise.

Will nano-structure catalysts and other stuff change the face of energy usage? Perhaps - in fact, I'm sure that as the science and technology develop, we'll see a lot of good things here, large and small. It could even be that this particular report is the one in a thousand that seeds a real, significant breakthrough. But you can't tell off the bat, and without some sort of filter you'll just drown in frothy speculation. That's the answer to the question of where's your jet pack.

Snark, or the end result of decades dealing with this stuff? I'll report, you decide...
posted by Devonian at 10:14 AM on October 18, 2016 [3 favorites]

It has been 81 0 days since metafilter heard about someone discovering how to turn CO2 into fuel.
posted by sfenders at 11:20 AM on October 18, 2016 [6 favorites]

So if I coat my teeth with these spikes and then stick my tongue in a wall outlet... I can get drunk?
posted by Hairy Lobster at 11:34 AM on October 18, 2016 [2 favorites]

No a catalyst lowers the activation energy barrier for a reaction.

k = A*exp(-E_a/RT), dude.
posted by mr_roboto at 11:47 AM on October 18, 2016 [1 favorite]

So if I coat my teeth with these spikes and then stick my tongue in a wall outlet... I can get drunk?

Your metabolism of the alcohol would greatly outpace the synthesis under those conditions.


So, I'll be able to take this camping and still get drunk without lugging around a massive cooler full of beer?

It would be easier, and lighter, to carry the beer than to carry the batteries required to power the contraption.

"magic stir bar" that you can use to turn your fresh can of Coke into a slightly-flat alco-soda by hooking it up to a battery

Hmmm so soda is normally carbonated at about 3.3 Volumes of CO2. Given a can is 330 ish ml that gives about 1L of CO2 at standard temperature and pressure (also chosen because it simplifies the math.) 1L of a gas is about 0.04 moles. Ethanol has a MW of 46, so about 2g. This would mean a beverage with an alcohol percentage of 0.6% meaning you would need 10 of these sodas to equal one decent beer. (assuming 100% conversion)


I think I went too meta for metafilter. My original post was a meta against the "I'm not here to educate you go read the 101 page" type of post. I do despair about the state of science education though, especially among journalists releasing breathless statements about major change.
posted by koolkat at 12:50 PM on October 18, 2016 [1 favorite]

koolkat: "This would mean a beverage with an alcohol percentage of 0.6% "

Cool, that means it's legal to sell on Sundays too!
posted by caution live frogs at 1:37 PM on October 18, 2016 [1 favorite]

k = A*exp(-E_a/RT), dude.

How dare you, my mother is a saint!
posted by the uncomplicated soups of my childhood at 2:25 PM on October 18, 2016 [3 favorites]

Let's use molten salt thorium fluoride reactors to make electricity, and get a liquid fuel as stored energy when there is a surplus of power.
posted by MikeWarot at 5:36 PM on October 18, 2016 [2 favorites]

I wonder what ever happened to the Morphine producing yeast, or was it heroin producing yeast? Now I wonder if that pink drug is from that yeast? Never mind, engines really have to change to use more than 10% ethanol, since it destroys the tubing in my old car already.
posted by Oyéah at 6:39 PM on October 18, 2016

Let's use molten salt thorium fluoride molten fluoride

Would never pass local zoning laws. that stuff is bad for ya, and it'll control your mind!
posted by 922257033c4a0f3cecdbd819a46d626999d1af4a at 6:49 PM on October 18, 2016

They also cleverly hide their efficiency in Faradaic Efficiency in that for every bit of energy they put in 63% of it leads to the production of ethanol. No mention on the rate of mass conversion or batch size for running the reaction.

Even that isn’t true. Faradaic efficiency tells you how many electrons went into the product you want vs. the byproducts you don’t, but for energy what matters is electron‐volts.

The electrons that turned CO₂ and H₂O to C₂H₆O had more volts that was strictly necessary to re‐work the bonds, and this is another source of inefficiency.†

I don’t know the precise magnitude of that inefficiency, but I do know that even the paper’s authors admit:

The overpotential (which might be lowered with the proper electrolyte, and by separating the hydrogen production to another catalyst) probably precludes economic viability for this catalyst

That’s not the kind of thing you want to read in a purportedly world‐changing paper.

It’s an interesting reaction, but that’s all it is. It’s notable in that the synthesis happens all in one step, not for its efficiency.

†If you lower the voltage to bring down this loss, Faradaic efficiency drops, as show in fig. 5. So does the reaction rate.
posted by Fongotskilernie at 7:54 PM on October 18, 2016

Lalochezia was quick off the mark on the general energy balance issue. Others have hit the follow on point clearly--this is at best carbon neutral if you have inputs that use no energy.

An additional issue that applies to any CO2 scrubbing idea, unless you're planning to install on smokestacks over fossil fuel plants, is that you are also trying to move carbon from an area where it is present in trace quantities (the atmosphere, at around 400 ppm) to a high-concentration sink. It's uphill all the way*.

Also, a reminder that photosynthesis is not efficient. Often natural processes embarrass our best engineers with their capabilities, but this is a rare exception. Photosynthesis gets a couple percent (or less) of the incoming radiation. Simple silicon photovoltaics have been an order of magnitude better for ages.

*The seed-the-ocean-with-iron-to-grow-algae was probably the most promising approach, as it used massive amounts of sunlight being "wasted" in an ocean desert to power the process, but it hasn't panned out and seems to do more harm than good.
posted by mark k at 10:26 PM on October 18, 2016

According to Wikipedia, Ethanol has an energy density of 20.9MJ/L -- a little more than half of gasoline, but 8-20x Lithium Ion. But, this reaction seems to be *reversible*, just in terms of feedstock. Ethanol combusts into CO2 and Water, and this new trick inverts the process at 63% efficiency.

Now, granted. Lithium Ion cells appear to have a 99% efficiency on charge. But, you know, this feedstock is much cheaper, and potentially scales much, much larger. Clean energy has always had less of a generation problem and more of a storage and transport issue.

I suppose a real question is, how fragile is this catalyst? How many liters can it run through?

(Anyone see fault in my analysis here?)
posted by effugas at 12:50 AM on October 19, 2016

I will believe this is a real, workable, feasible, thing when it is actively producing ethanol in usable quantities by slurping CO2 out of the atmosphere.
posted by sotonohito at 7:17 AM on October 19, 2016

(Anyone see fault in my analysis here?)

The 63% efficiency is not the same as "energy recovered" during recharge. You also need to add the cost of CO2 into the equation--atmospheric CO2 is not usable for this process. It's not necessarily scalable with the catalysts used. Ethanol when it burns will not be converted to electricity with the efficiency of a lithium battery. There are cheaper ways to store energy at the grid level.

The storage point is good but basically there are lots of options which have the problem of not actually being cost effective. Hydrogen produced by electrophoresis from renewable energy sources, for example, could handle the portable storage and be burned to provide power at night (or move cars). But IIUC the dealbreaker with current system is the electrodes are expensive and don't last forever. So it's a non-starter. There's research there but it's far from the most promising approach to store large amounts of power. Something coming in behind that, with the same basic approach and its own challenges, is in the realm of "nice to have lots of options in research but unlikely to make an impact."

Since practically speaking you'd need to do this with waste carbon from industrial processes it's really not a long term solution--even the paper calls it a transition approach. You get an extra pass out of the energy you burned the first time, and then some waste. Can you get it up an running before you need the CO2 producing industries retired? Probably not, though you might get it working before they are retired at the rate we're going.
posted by mark k at 7:57 AM on October 19, 2016