Diamonds? A Sexy Spin On Carbon Capture Tech

[Meredith Poor + 883]

"During the production of just one one-carat diamond, Aether estimates it removes around 20 metric tonnes of CO2 from the atmosphere, equivalent to the yearly emissions of the average American."

If one does a keyword search 'diamond carat equivalent in grams' one finds that 1 carat = .2 grams

The weight ratio of carbon to oxygen in CO2 is 12 to (2 x 16) or 32. So 20 metric tonnes (or 20,000,000 grams) of CO2 would be 5,454,545 grams of carbon and 14,545,455 grams of oxygen.

So where does the rest of the carbon go?

[markslawson + 1,042]

5 hours ago, Meredith Poor said:

So where does the rest of the carbon go?

An excellent question. The worrying part is that the figure is repeatedly endlessly in the media coverage without anyone bothering to question it. Out of curiosity I even looked at details of the process. This guy is seriously proposing to filter the carbon out of the air itself.. as CO2 is about 400 parts per million, or 0.04 per cent of air, that's a lot of air to pass through filters, even without assuming some slippage in the process. The carbon has to be compressed, and he's claiming all the energy for this will come from renewable sources.. Well, I won't be investing in the company.. 

[Meredith Poor + 883]

2 hours ago, markslawson said:

An excellent question. The worrying part is that the figure is repeatedly endlessly in the media coverage without anyone bothering to question it. Out of curiosity I even looked at details of the process. This guy is seriously proposing to filter the carbon out of the air itself.. as CO2 is about 400 parts per million, or 0.04 per cent of air, that's a lot of air to pass through filters, even without assuming some slippage in the process. The carbon has to be compressed, and he's claiming all the energy for this will come from renewable sources.. Well, I won't be investing in the company.. 

There are several easy ways to remove CO2 from the atmosphere, a common one is to mix ammonia and water. When this mixture reacts with CO2, it makes ammonium bicarbonate. Heating up the bicarbonate breaks the molecule into CO2, water, and ammonia.

The volume of air needed at 400 PPM to make a 1 carat diamond is about 8 cubic meters - probably the volume of a closet or small bathroom.

Keyword search 'CO2 reduction to graphite'.

https://www.nature.com/articles/s41467-020-20380-0

Graphite would be the 'feedstock' to the press that would make the diamond.

[nsdp + 449]

You have never had thermodynamics have you. You will create about 3-4kg of CO2 for every Kg  you remove.  Smooth move Sherlock.

"In 1941, an agreement was made between the General Electric (GE), Norton and Carborundum companies to further develop diamond synthesis. They were able to heat carbon to about 3,000 °C (5,430 °F) under a pressure of 3.5 gigapascals (510,000 psi) for a few seconds. https://en.wikipedia.org/wiki/Synthetic_diamond

[markslawson + 1,042]

20 hours ago, Meredith Poor said:

There are several easy ways to remove CO2 from the atmosphere, a common one is to mix ammonia and water. When this mixture reacts with CO2, it makes ammonium bicarbonate. Heating up the bicarbonate breaks the molecule into CO2, water, and ammonia.

MP - for heaven sake please concentrate! I'm well aware that there are chemical ways in which carbon can be removed from the atmosphere. I was going to add in a line about air recycling systems on submarines but I thought that it was too obvious. But even if the point you're making about the volume of air is correct - and I'm willing to listen on that point - it wasn't even the main point I was making. Go back and look at the post. The energy required to turn graphite into diamond is very substantial indeed, and its all supposed to come from renewable energy. I don't think so. As for the link you cite go back and look at that - its a scientific paper. Now if you want to turn carbon in the air into graphic reasonably cost effectively okay, the process has promise. Let's see a commercial application, then you can lecture. Leave it with you..     

[Andrei Moutchkine + 828]

39 minutes ago, markslawson said:

MP - for heaven sake please concentrate! I'm well aware that there are chemical ways in which carbon can be removed from the atmosphere. I was going to add in a line about air recycling systems on submarines but I thought that it was too obvious. But even if the point you're making about the volume of air is correct - and I'm willing to listen on that point - it wasn't even the main point I was making. Go back and look at the post. The energy required to turn graphite into diamond is very substantial indeed, and its all supposed to come from renewable energy. I don't think so. As for the link you cite go back and look at that - its a scientific paper. Now if you want to turn carbon in the air into graphic reasonably cost effectively okay, the process has promise. Let's see a commercial application, then you can lecture. Leave it with you..     

Diamond is actually quite plentiful in the nature. This is why De Beers exists. Even the jewelry grade diamond is too plentiful and would cost next to nothing if they opened the floodgates. I see a bright future for diamond as superior anthracite coal. Very light on ash disposal!

[Meredith Poor + 883]

3 hours ago, markslawson said:

MP - for heaven sake please concentrate! I'm well aware that there are chemical ways in which carbon can be removed from the atmosphere. I was going to add in a line about air recycling systems on submarines but I thought that it was too obvious. But even if the point you're making about the volume of air is correct - and I'm willing to listen on that point - it wasn't even the main point I was making. Go back and look at the post. The energy required to turn graphite into diamond is very substantial indeed, and its all supposed to come from renewable energy. I don't think so. As for the link you cite go back and look at that - its a scientific paper. Now if you want to turn carbon in the air into graphic reasonably cost effectively okay, the process has promise. Let's see a commercial application, then you can lecture. Leave it with you..     

"The energy required to turn graphite into diamond is very substantial indeed, and its all supposed to come from renewable energy." You and I may have a different concept of what 'very substantial' means. If we're talking about trainloads of graphite going into an old coal mine, then we're talking about all the energy going back into that mine in comparison to the amount that came out in the first place. Heating .2 grams of graphite to make a 1 carat diamond might set you back a kilowatt-hour, or roughly the output of one 200 watt solar panel on a typical day.

[Andrei Moutchkine + 828]

16 minutes ago, Meredith Poor said:

"The energy required to turn graphite into diamond is very substantial indeed, and its all supposed to come from renewable energy." You and I may have a different concept of what 'very substantial' means. If we're talking about trainloads of graphite going into an old coal mine, then we're talking about all the energy going back into that mine in comparison to the amount that came out in the first place. Heating .2 grams of graphite to make a 1 carat diamond might set you back a kilowatt-hour, or roughly the output of one 200 watt solar panel on a typical day.

Industrial diamonds are not made by "heating" but by blowing up high explosives in a heavily armored box. Jewelry grade "cultured diamonds" are made by a CVD/PVD type process depositing nanoscale layers under vacuum.

[Rob Plant + 2,610]

A British Entrepreneur Is Making ‘Zero-Impact Diamonds’ That Remove Carbon Dioxide From the Air

https://robbreport.com/style/jewelry/dale-vince-british-entrepreneur-zero-impact-diamonds-1234578688/

 

[Andrei Moutchkine + 828]

4 hours ago, Rob Plant said:

A British Entrepreneur Is Making ‘Zero-Impact Diamonds’ That Remove Carbon Dioxide From the Air

https://robbreport.com/style/jewelry/dale-vince-british-entrepreneur-zero-impact-diamonds-1234578688/

 

Aha. Yet another elderly gentleman founder with proper executive style grey hair, who is some kind of sir is a telltale sign of the business being fraudulent. Those guys occupy the same niche the champion Girl Scout cookie selling teams do in US. Examples are plentiful - Sinclair, Bronson, Dyson and the DeLorean muppet they caught smuggling coke using the Concorde. Do I need to explain any of these?

Problems from this description alone.

a) You cannot make methane out of CO2 and H2. You need CO, giving syngas. CO2 is not an easily available source of CO. Because

https://en.wikipedia.org/wiki/Water–gas_shift_reaction

CO + H₂O ⇌ CO₂ + H₂

where CO and H2 are never found on the same side of the equation

b) The process is obviously way too high energy PVD variety. This likely is caused by methane being electrically inert. There are much gentler CVD ways to deposit diamond if you use something more easily ionized.

In the first approximation, I suspect a British government plot to make diamond part having complicated shapes?

If I were them, I would start with acetylene instead of methane, which is what is used to cook carbon fiber parts all the way to C/C (carbon fiber in graphite)

https://en.wikipedia.org/wiki/Reinforced_carbon–carbon

If you keep cranking it up, it is not exceptionally impossible that you will end up with some kind of next level beats, say nanotube reinforced londsdeite (planar diamond) AFAIK, has the procedure never been combined with PVD. My explanation is that it fails due to acytelene soot being in a very unusual (for carbon) cathode configuration (own work, AFAIK). (This is really my reason to why you cannot burn some other gas to make carbon fiber)

c) There is no market for synthetic diamond in jewelry. It has to be labelled as "cultured" and is strongly de-emphasized. The detection is trivial by means of shining a UV light on the stone and watching the afterglow. Synthetic diamond maintains an afterglow for minutes after exposure, because it is significantly closer to the perfect crystalline grid.

Also see the disappointing story of

https://en.wikipedia.org/wiki/Apollo_Diamond later

https://en.wikipedia.org/wiki/Scio_Diamond_Technology_Corporation

Which started out as a cool startup planning to make high-temperature semiconductors out of doped diamond, but ended up some kind of scam.

[markslawson + 1,042]

23 hours ago, Andrei Moutchkine said:

Diamond is actually quite plentiful in the nature.

Oh yes, I agree.. no real need for artificial diamonds.. 

[markslawson + 1,042]

20 hours ago, Meredith Poor said:

Heating .2 grams of graphite to make a 1 carat diamond might set you back a kilowatt-hour, or roughly the output of one 200 watt solar panel on a typical day.

Now I know you've lost it... Note this item from the MIT Technology Review

Converting graphite into diamond has been a long held dream of alchemists the world over. In the modern era, materials scientists have puzzled over this process because it’s hard to work out why the conversion is so hard.

Measure the free energy of graphite and diamond and you’ll find they are more or less the same. That implies that converting one into the other ought to be easy.

And yet in experiments, the conversion only works at temperatures well above 1700K and at pressures in excess of 12 GigaPascals. It’s no wonder, then, that diamond is so rare and valuable

But why should graphite be so reluctant to make the change? Today, Rustam Khaliullin at the Swiss Federal Institute of Technology Zurich and a few buddies say they think they know why. These guys have created a computer model of the process which has identified the reason why diamond is so reluctant to form.

Granted there have been advances since then, but the original post was about the ability to filter carbon out of air with some degree of cost effectiveness. Nothing was said about diamonds being easier to form or indeed, simply being able to wave a wand to create them.

Anyway, I'll leave it with you.. hope you get back on an even keel when next we meet.. 

[Meredith Poor + 883]

2 hours ago, markslawson said:

Now I know you've lost it...

hope you get back on an even keel when next we meet.. 

Certainly presumptive language.

People confuse 'high temperature' with 'high energy'. When you shuffle across the floor on a cold dry day and get a spark from touching something, the voltage is 50,000 volts. The energy is in milliwatts.

A watt-second is the energy needed to raise one gram of water one degree Celsius. 1700 degrees would then require 1700 watt-seconds for water. .2 grams of carbon (at a molecular weight of 12) is first 2/3s of the amount of energy for 1 gram of water (molecular weight of 18), multiplied by .2 (1/5th of a gram). 1200 watt-seconds / 5 = 240. 240 watt-seconds is 4 watt-minutes or 1/15th of a watt-hour.

Similarly, pressure has little to do with energy. The motor from a kitchen blender might be enough to crank in 12 giga-pascals with the right reduction drive train.

You can demonstrate to everyone that you think you're surrounded by fools. I'm sure they'll appreciate your attitude.

[Andrei Moutchkine + 828]

4 minutes ago, markslawson said:

Now I know you've lost it... Note this item from the MIT Technology Review

Converting graphite into diamond has been a long held dream of alchemists the world over. In the modern era, materials scientists have puzzled over this process because it’s hard to work out why the conversion is so hard.

Measure the free energy of graphite and diamond and you’ll find they are more or less the same. That implies that converting one into the other ought to be easy.

And yet in experiments, the conversion only works at temperatures well above 1700K and at pressures in excess of 12 GigaPascals. It’s no wonder, then, that diamond is so rare and valuable

But why should graphite be so reluctant to make the change? Today, Rustam Khaliullin at the Swiss Federal Institute of Technology Zurich and a few buddies say they think they know why. These guys have created a computer model of the process which has identified the reason why diamond is so reluctant to form.

Granted there have been advances since then, but the original post was about the ability to filter carbon out of air with some degree of cost effectiveness. Nothing was said about diamonds being easier to form or indeed, simply being able to wave a wand to create them.

Anyway, I'll leave it with you.. hope you get back on an even keel when next we meet.. 

I have a simpler explanation. Graphite tends to be an electrical anode. To get it to form some kind of new bond with itself, you also need a C cathode. (which I presume what the CVD guys are doing, when they are making diamond without the graphite intermediate)

From

https://en.wikipedia.org/wiki/Standard_electrode_potential_(data_page)

is the C anode potential -0.43V (CO2, aq. oxalic acid) and C anode 0,13V (methane dry, methanol)

Aha, I see what the British fellow is up to. I see two more positions I didn't realize  were there), a

-0.11 anode (CO2, aq. formic) and 0.5V (CO2, methane in the presence of H2O), 0.52V cathodes (pure C in the presence of H2O) Even though it is not in the Wiki, I found the value for acetylene (which is what is used to create graphite grade carbon fiber) It is 0,731V, largest yet. Almost a match for -0.8277 for H2 electrolytically restored from liquid water. (not sure what's the deal with the 4th digit, but the -0.001 bit is canonically attributed to OH- radical left behind, which the chem geeks conjure for plausible deniability of their acid-base model being broken. Should really be H+ (a hydrogen cation) but it is forbidden and exists for the benefit of visiting physics geeks who follow a different set of hadiths)

This explains the methane (it being a cathode) We've got everything we need to nudge the equilibrium of the all-important

https://en.wikipedia.org/wiki/Water–gas_shift_reaction

CO + H₂O ⇌ CO₂ + H₂

Now, there could be plenty of interesting environmental applications of this tech, except that making diamond isn't one of them. Why would anybody want to do that?!?

So, lets say we are trying to make something actually useful, like an improved version of direct methanol fuel cell (which works the same as methane electrochemically speaking, so make it a direct LNG fuel cell. The stuff is too cold to participate in any natural chemistry)

Can I improve it? You bet. By switching to a more powerful acetylene cathode that I like so much

Another very interesting relevant electrode is HO2 (hydroxyl radical, aka hydrogen superoxide) which equates to -0.13V, which is exactly enough to cancel the CO2 cathode, producing 0V hydrogen, as it should, that being the reference zero electrode) You could think of it as the elusive base oxygen. (which officially exists, though rarely) or even more elusive acid hydrogen (way weird, given that H is kinda an alkali metal. Which are normally highly negative. Some kind of hypothetical

https://en.wikipedia.org/wiki/Metallic_hydrogen

supposedly exists in the core of gas giant planets, which gives us hope, it being lots closer to us than peculiarly gigantic black hole in the galaxy far, far away, where most of the interesting physics discoveries are made. The reason I brought it up is that the pressure required to make that stuff is allegedly far in excess of what is required for diamond. It is known to break diamond anvils when you attempt to stack them to make it. Thus, we can hypothesize that electromagnetically inducing a hydrogen state equivalent to a proper metal, it'd be the same as that much pressure? Only in plasma, which works the same (with those standard electrode voltage being actually eV, electron volts)

Last, but not least we extend the water shift reaction with superoxidation states. Most specifically hydrogen peroxide, H2O2, an oxidizer rather than the current convention of it being an incredibly weak acid. With one of my pet peeves of mine the better model of water being "a very weak solution of H2O2" The electrode potential? Still being measured in proper PH-netural fashion producing results between -0,61 and -0.91 depending on concentration. See, this sort of thing always makes me question the validity of that -0,01 (2nd digit) OK, I think I found it. Deconstructing the

https://en.wikipedia.org/wiki/Standard_hydrogen_electrode

at reference 0V, we find that it is actually 4,44V +/- mysterious 0.02V. Given that this is the entire potential available in an electrolytic cell, between - to +, we got the 2x0.01 (hydrogen acting as an acid or base) Now, that wouldn't be possible given the standard hydrogen half cell

https://en.wikipedia.org/wiki/Half-cell

but potentially possible if connected to a dual "hydrogen cell" (same difference, except for sign reversal, as well as substitution of tired old "salt bridge" with "proton exchange membrane" Which makes it sufficiently glamorous as to be potentially eligible for EU environmental subsidies" Do we get to double the voltage again? Not sure, but maybe somewhat true, based on comparison to tantalum electrolytic capacitor which actually has two-cross connected "half-caps" with distinct anode and cathode, to emulate a more powerful version of regular electrolytic capacitor, which does not care about which end is which.

I cannot access the MIT Tech review article for free, but they seem to be talking about surface potentials, which possibly related to the

https://en.wikipedia.org/wiki/Double_layer_(surface_science)

Which (among other things) is the substance that enables the peaceful coexistence of + and - surface charges at the boundary between an electrode and electrolyte in electrolytic half-cell. Also, regular human cell. Personally, I find this model a bit contrived in this case.

Now, we get 0.731 +/- 0.13 which produces 0;6 (just under official water/peroxide boundary 0.61 and -0.86. which is over -0.81 required for electrolytic reduction of H2. (at the expense of water getting deprotonated/becoming more acid-like by means of squiring OH- radicals. Which I argue should be just H+ and oxidizer-like.

If I lost you by now, the purpose of sorting electrode potentials is because this is a great way to understand some solvated or plasma mess by sticking electrodes into it. Using the general principle that  oppositely charged things of the highest potential will preferentially be attracted to next-highest potential with opposite signs. Think two goalies/captains taking turns picking two soccer teams. Normally, each simply picks the next strongest player available, but that could be some exceptions to that.

Now, knowing that, we can skip a whole bunch of experiments, brute forcing the potential matches. For example, lets see this interesting claim related to adding peroxide to water shift.

H2O2 → O2 + 2H+ + 2e-	Eo = -0.682 V
H2O2 + 2H+ + 2e- → 2H2O	Eo = 1.776 V

All the parts are the same and should be in equilibrium. Except for some kind of free energy preferencing oxidation of hydrogen to regular water, as opposed to dissociation of peroxide into H2O2, oxygen gas and two 2H+, With the difference being

1.776 - (0.682 * 2) = 0.412

Do we have a good candidate in the table of standard electrodes? Yes, we do. There is a 0.401 claimed for mysterious direct dissociation of water and oxygen into 4OH-, at a 0.401 Which, in itself, makes no electrical sense, with one OH- good for a microscopic variation of 0,001, barely off zero (This based on an obscure 1997 paper..As it stands, we are dealing with an ionic solution of electron holes? which works like an electride with an opposite sign.

There is also a substance called ferrocene at 0.4, likely to have tremendously interesting catalytic properties with respect to making diamond.

Now, can we nudge the combined equilibrium into a different direction? In fact, we can. I've actually managed a runaway conversion of water to ever more concentrated peroxide using a bit of household bleaching detergent (99% inert binders and nanoscopic amount of advanced "peroxide formation promoters") and this interesting substance.

https://en.wikipedia.org/wiki/Fenton's_reagent

Which you can think of as mother of all bleaches. Used in industrial water treatment for "deinking" (destroying any kind of colored ink, regardless if it is water solvable or not) and breaking up any complex hydrocarbon into water and CO2. Think about the implications! This hints at the existence of universal direct fuel cell, which could use any hydrocarbon fuel. A plug-in replacement for ICE with no moving part allowed arbitrarily slow-mo operation in a liquid phase!

OK, lets say we still want to make diamonds instead of that. Then, we've got ourself a really good reference for an oxidizer that is really not an acid a base. Note that the chem geeks made an exception for the Fenton's reagent, allowing the positive charge carriers be a mixture of regular hydroxil radicals OH- and H+ (forbidden hydrons) So, how do we continue the burn to crispy coal, beyond the CO2? That's a reduction, instead of oxidation. So, we need a reducer agent that is also an acid. From the top of my head, (over)concentrated sulfuric acid does that (turns anything organic into crispy coal much larger in size) Apparently, the even stronger oxidizing mineral acid which allows concentrations in excess of 100% (like oleum) produces an explosion (and crispy coal powdered very small) So, we are looking into an electrical emulation of that in the gaseous phase.

Which gets as back to acetylene. Which is known to produce fine sticky carbon soot (lamp soot) even if you burn it with pure oxygen, which is a step in the right direction. What about ozone (as if an acetylene torch was not scary enough) Lets see. The "scientific consensus" seems to be for it being 2.07V, our most powerful cathode so far.

However, some important chem guy came out of retirement to issue this correction.

https://www.researchgate.net/publication/247012121_The_reduction_potential_of_the_couple_O3O-3Consequences_for_mechanisms_of_ozone_toxicity

There is no abstract for this paper. The electrode potential was based on an old value for the Gibbs energy of formation of the hydroxyl radical. The revised value (Armstrong et al., Pure Appl. Chem. 87, 1139-1150 (2015) is O3(aq) + e− -> O3 ·– E° = +1.03 ± 0.02 V

Which seems to be 1/2 of previous +/- 0.01V. Alas, chem guy's opinions about microvolts are entirely unreliable, because the measurements depends on existence of a known unobtainium - perfectly inert PH7 water. Which sound like de-ionized / dielectric to me. This be based on the observable that decomposition of 2O2 produces only one ozone which donates two electrons. The other product is more likely to be some kind of half a singlet oxygen radical, which invariably ends up having a valency of 1/2 both sides of equilibrium and resists stoichiometry, on the account of 1/2 not having a common denominator with anything. (there is also a similar case for 3O2 producing an O3 and O3- (ozonide) which you can think as 2/3 and 3/2 fractional valencies which cancel out well enough)

This is a beautiful illustration how more flexible mind of nuclear physics geeks can solve the conundrum presented by singlet oxygen radicals to the chem geeks, while forcing their own set of hadith equally arbitrary. Behold the

https://en.wikipedia.org/wiki/Electron_capture

mechanism? Did you see that electron donated? Now you don't. What really happened is that the emitter caught the electron back, which caused one of the neutrons to change into a proton! and what we really emitted is an electron-neutrino (which is distinct from all the other neutrinos in that it actually does have regular mass and interacts with conventional matter) Why wouldn't they call it a secondary emission of a neutron, which happens to have an unusually low energy (i.e. being thermal as opposed to fast) The obvious self interest is the avoidance of discussion of

a) Producing a novel form of a radioactive toxic waste

b) Lack of observable next level can of whoop as due to engagement of the strong nuclear force instead of regular one.

The way I see it is that BS is easily translated.to something meaningful outside of nuclear physics is by observing that some of the unspeakable

https://en.wikipedia.org/wiki/Hydron_(chemistry)

H+ carriers might actually be a deuteron, arising from some of the hydrogen involved being deuterium, which got a neutron to spare. (Which than appears fairly low energy in terms of electron-volts, say 0,001V instead of 0.01 eV or 0.1 eV) At which point do we get into "low power nuclear reactions" (polite rebadging of cold fusion) by observing that what we leave behind is actually benign heavy water with some H+ carriers which are actual physical protons, which work exactly the same as electrons up to the opposite sign, so we might as well rebadge them into "electron holes" the way semiconductor guys do

 

 

 

 

 

 

[Eric Gagen + 713]

On 11/7/2021 at 11:45 AM, Meredith Poor said:

"During the production of just one one-carat diamond, Aether estimates it removes around 20 metric tonnes of CO2 from the atmosphere, equivalent to the yearly emissions of the average American."

If one does a keyword search 'diamond carat equivalent in grams' one finds that 1 carat = .2 grams

The weight ratio of carbon to oxygen in CO2 is 12 to (2 x 16) or 32. So 20 metric tonnes (or 20,000,000 grams) of CO2 would be 5,454,545 grams of carbon and 14,545,455 grams of oxygen.

So where does the rest of the carbon go?

Actually, no they do NOT claim that they remove 20 tonnes of CO2 in the production of 1 carat of diamond.  They claim to avoid the emission of 20 tonnes of CO2 which would otherwise be part of the process of mining diamonds. 

That claim is spurious though, because the correct comparison is not with mined diamonds, but with other lab grown diamonds.  In that case the 'savings' is much smaller, and possibly negative (i.e. worse than the alternatives) depending on the initial cost, efficiency and reliability of the equipment they plan to use to make the diamonds with.  

This scheme is not to different from mining etherium or bitcoin.  The difference is that they are making artificial diamonds (which are neither rare nor particularly valuable) instead of blockchains, and counting on consumers to be ignorant or gullible enough to pay a high enough price for the diamonds to make the process worthwhile.  

[Meredith Poor + 883]

6 hours ago, Andrei Moutchkine said:

I have a simpler explanation. Graphite tends to be an electrical anode. To get it to form some kind of new bond with itself, you also need a C cathode. (which I presume what the CVD guys are doing, when they are making diamond without the graphite intermediate)

From

https://en.wikipedia.org/wiki/Standard_electrode_potential_(data_page)

is the C anode potential -0.43V (CO2, aq. oxalic acid) and C anode 0,13V (methane dry, methanol)

Aha, I see what the British fellow is up to. I see two more positions I didn't realize  were there), a

-0.11 anode (CO2, aq. formic) and 0.5V (CO2, methane in the presence of H2O), 0.52V cathodes (pure C in the presence of H2O) Even though it is not in the Wiki, I found the value for acetylene (which is what is used to create graphite grade carbon fiber) It is 0,731V, largest yet. Almost a match for -0.8277 for H2 electrolytically restored from liquid water. (not sure what's the deal with the 4th digit, but the -0.001 bit is canonically attributed to OH- radical left behind, which the chem geeks conjure for plausible deniability of their acid-base model being broken. Should really be H+ (a hydrogen cation) but it is forbidden and exists for the benefit of visiting physics geeks who follow a different set of hadiths)

This explains the methane (it being a cathode) We've got everything we need to nudge the equilibrium of the all-important

https://en.wikipedia.org/wiki/Water–gas_shift_reaction

CO + H₂O ⇌ CO₂ + H₂

Now, there could be plenty of interesting environmental applications of this tech, except that making diamond isn't one of them. Why would anybody want to do that?!?

So, lets say we are trying to make something actually useful, like an improved version of direct methanol fuel cell (which works the same as methane electrochemically speaking, so make it a direct LNG fuel cell. The stuff is too cold to participate in any natural chemistry)

Can I improve it? You bet. By switching to a more powerful acetylene cathode that I like so much

Another very interesting relevant electrode is HO2 (hydroxyl radical, aka hydrogen superoxide) which equates to -0.13V, which is exactly enough to cancel the CO2 cathode, producing 0V hydrogen, as it should, that being the reference zero electrode) You could think of it as the elusive base oxygen. (which officially exists, though rarely) or even more elusive acid hydrogen (way weird, given that H is kinda an alkali metal. Which are normally highly negative. Some kind of hypothetical

https://en.wikipedia.org/wiki/Metallic_hydrogen

supposedly exists in the core of gas giant planets, which gives us hope, it being lots closer to us than peculiarly gigantic black hole in the galaxy far, far away, where most of the interesting physics discoveries are made. The reason I brought it up is that the pressure required to make that stuff is allegedly far in excess of what is required for diamond. It is known to break diamond anvils when you attempt to stack them to make it. Thus, we can hypothesize that electromagnetically inducing a hydrogen state equivalent to a proper metal, it'd be the same as that much pressure? Only in plasma, which works the same (with those standard electrode voltage being actually eV, electron volts)

Last, but not least we extend the water shift reaction with superoxidation states. Most specifically hydrogen peroxide, H2O2, an oxidizer rather than the current convention of it being an incredibly weak acid. With one of my pet peeves of mine the better model of water being "a very weak solution of H2O2" The electrode potential? Still being measured in proper PH-netural fashion producing results between -0,61 and -0.91 depending on concentration. See, this sort of thing always makes me question the validity of that -0,01 (2nd digit) OK, I think I found it. Deconstructing the

https://en.wikipedia.org/wiki/Standard_hydrogen_electrode

at reference 0V, we find that it is actually 4,44V +/- mysterious 0.02V. Given that this is the entire potential available in an electrolytic cell, between - to +, we got the 2x0.01 (hydrogen acting as an acid or base) Now, that wouldn't be possible given the standard hydrogen half cell

https://en.wikipedia.org/wiki/Half-cell

but potentially possible if connected to a dual "hydrogen cell" (same difference, except for sign reversal, as well as substitution of tired old "salt bridge" with "proton exchange membrane" Which makes it sufficiently glamorous as to be potentially eligible for EU environmental subsidies" Do we get to double the voltage again? Not sure, but maybe somewhat true, based on comparison to tantalum electrolytic capacitor which actually has two-cross connected "half-caps" with distinct anode and cathode, to emulate a more powerful version of regular electrolytic capacitor, which does not care about which end is which.

I cannot access the MIT Tech review article for free, but they seem to be talking about surface potentials, which possibly related to the

https://en.wikipedia.org/wiki/Double_layer_(surface_science)

Which (among other things) is the substance that enables the peaceful coexistence of + and - surface charges at the boundary between an electrode and electrolyte in electrolytic half-cell. Also, regular human cell. Personally, I find this model a bit contrived in this case.

Now, we get 0.731 +/- 0.13 which produces 0;6 (just under official water/peroxide boundary 0.61 and -0.86. which is over -0.81 required for electrolytic reduction of H2. (at the expense of water getting deprotonated/becoming more acid-like by means of squiring OH- radicals. Which I argue should be just H+ and oxidizer-like.

If I lost you by now, the purpose of sorting electrode potentials is because this is a great way to understand some solvated or plasma mess by sticking electrodes into it. Using the general principle that  oppositely charged things of the highest potential will preferentially be attracted to next-highest potential with opposite signs. Think two goalies/captains taking turns picking two soccer teams. Normally, each simply picks the next strongest player available, but that could be some exceptions to that.

Now, knowing that, we can skip a whole bunch of experiments, brute forcing the potential matches. For example, lets see this interesting claim related to adding peroxide to water shift.

H2O2 → O2 + 2H+ + 2e-	Eo = -0.682 V
H2O2 + 2H+ + 2e- → 2H2O	Eo = 1.776 V

All the parts are the same and should be in equilibrium. Except for some kind of free energy preferencing oxidation of hydrogen to regular water, as opposed to dissociation of peroxide into H2O2, oxygen gas and two 2H+, With the difference being

1.776 - (0.682 * 2) = 0.412

Do we have a good candidate in the table of standard electrodes? Yes, we do. There is a 0.401 claimed for mysterious direct dissociation of water and oxygen into 4OH-, at a 0.401 Which, in itself, makes no electrical sense, with one OH- good for a microscopic variation of 0,001, barely off zero (This based on an obscure 1997 paper..As it stands, we are dealing with an ionic solution of electron holes? which works like an electride with an opposite sign.

There is also a substance called ferrocene at 0.4, likely to have tremendously interesting catalytic properties with respect to making diamond.

Now, can we nudge the combined equilibrium into a different direction? In fact, we can. I've actually managed a runaway conversion of water to ever more concentrated peroxide using a bit of household bleaching detergent (99% inert binders and nanoscopic amount of advanced "peroxide formation promoters") and this interesting substance.

https://en.wikipedia.org/wiki/Fenton's_reagent

Which you can think of as mother of all bleaches. Used in industrial water treatment for "deinking" (destroying any kind of colored ink, regardless if it is water solvable or not) and breaking up any complex hydrocarbon into water and CO2. Think about the implications! This hints at the existence of universal direct fuel cell, which could use any hydrocarbon fuel. A plug-in replacement for ICE with no moving part allowed arbitrarily slow-mo operation in a liquid phase!

OK, lets say we still want to make diamonds instead of that. Then, we've got ourself a really good reference for an oxidizer that is really not an acid a base. Note that the chem geeks made an exception for the Fenton's reagent, allowing the positive charge carriers be a mixture of regular hydroxil radicals OH- and H+ (forbidden hydrons) So, how do we continue the burn to crispy coal, beyond the CO2? That's a reduction, instead of oxidation. So, we need a reducer agent that is also an acid. From the top of my head, (over)concentrated sulfuric acid does that (turns anything organic into crispy coal much larger in size) Apparently, the even stronger oxidizing mineral acid which allows concentrations in excess of 100% (like oleum) produces an explosion (and crispy coal powdered very small) So, we are looking into an electrical emulation of that in the gaseous phase.

Which gets as back to acetylene. Which is known to produce fine sticky carbon soot (lamp soot) even if you burn it with pure oxygen, which is a step in the right direction. What about ozone (as if an acetylene torch was not scary enough) Lets see. The "scientific consensus" seems to be for it being 2.07V, our most powerful cathode so far.

However, some important chem guy came out of retirement to issue this correction.

https://www.researchgate.net/publication/247012121_The_reduction_potential_of_the_couple_O3O-3Consequences_for_mechanisms_of_ozone_toxicity

There is no abstract for this paper. The electrode potential was based on an old value for the Gibbs energy of formation of the hydroxyl radical. The revised value (Armstrong et al., Pure Appl. Chem. 87, 1139-1150 (2015) is O3(aq) + e− -> O3 ·– E° = +1.03 ± 0.02 V

Which seems to be 1/2 of previous +/- 0.01V. Alas, chem guy's opinions about microvolts are entirely unreliable, because the measurements depends on existence of a known unobtainium - perfectly inert PH7 water. Which sound like de-ionized / dielectric to me. This be based on the observable that decomposition of 2O2 produces only one ozone which donates two electrons. The other product is more likely to be some kind of half a singlet oxygen radical, which invariably ends up having a valency of 1/2 both sides of equilibrium and resists stoichiometry, on the account of 1/2 not having a common denominator with anything. (there is also a similar case for 3O2 producing an O3 and O3- (ozonide) which you can think as 2/3 and 3/2 fractional valencies which cancel out well enough)

This is a beautiful illustration how more flexible mind of nuclear physics geeks can solve the conundrum presented by singlet oxygen radicals to the chem geeks, while forcing their own set of hadith equally arbitrary. Behold the

https://en.wikipedia.org/wiki/Electron_capture

mechanism? Did you see that electron donated? Now you don't. What really happened is that the emitter caught the electron back, which caused one of the neutrons to change into a proton! and what we really emitted is an electron-neutrino (which is distinct from all the other neutrinos in that it actually does have regular mass and interacts with conventional matter) Why wouldn't they call it a secondary emission of a neutron, which happens to have an unusually low energy (i.e. being thermal as opposed to fast) The obvious self interest is the avoidance of discussion of

a) Producing a novel form of a radioactive toxic waste

b) Lack of observable next level can of whoop as due to engagement of the strong nuclear force instead of regular one.

The way I see it is that BS is easily translated.to something meaningful outside of nuclear physics is by observing that some of the unspeakable

https://en.wikipedia.org/wiki/Hydron_(chemistry)

H+ carriers might actually be a deuteron, arising from some of the hydrogen involved being deuterium, which got a neutron to spare. (Which than appears fairly low energy in terms of electron-volts, say 0,001V instead of 0.01 eV or 0.1 eV) At which point do we get into "low power nuclear reactions" (polite rebadging of cold fusion) by observing that what we leave behind is actually benign heavy water with some H+ carriers which are actual physical protons, which work exactly the same as electrons up to the opposite sign, so we might as well rebadge them into "electron holes" the way semiconductor guys do

An actual conversation based on research making a point of fact.

Amazing.

And,,,, appreciated.

Thanks.

[markslawson + 1,042]

16 hours ago, Andrei Moutchkine said:

Now, there could be plenty of interesting environmental applications of this tech, except that making diamond isn't one of them. Why would anybody want to do that?!?

So, lets say we are trying to make something actually useful, like an improved version of direct methanol fuel cell (which works the same as methane electrochemically speaking, so make it a direct LNG fuel cell. The stuff is too cold to participate in any natural chemistry)

Andrei - your extended post was so clever I didn't understand most of it. But you're saying there is a low energy way to transform graphite to diamond (although you point out that changing to diamond form is the least profitable use of the technology)? the company that was the subject of the original post seems to be using the high-energy route. The company literature talks of a "powerful reactor". But, anyway, is this low energy way widely used or something you realised? I wasn't about to work it out.   

[Eric Gagen + 713]

On 11/10/2021 at 5:16 PM, markslawson said:

Andrei - your extended post was so clever I didn't understand most of it. But you're saying there is a low energy way to transform graphite to diamond (although you point out that changing to diamond form is the least profitable use of the technology)? the company that was the subject of the original post seems to be using the high-energy route. The company literature talks of a "powerful reactor". But, anyway, is this low energy way widely used or something you realised? I wasn't about to work it out.   

The opposite - it's explaining (with a lot of detail) why you can NOT easily move from graphite to diamond.  The short answer is that even though they have similar atomic/molecular energy states and organization, the energy of reaction to transition from one to the other is huge, and cannot be reduced.  

[markslawson + 1,042]

7 hours ago, Eric Gagen said:

The opposite - it's explaining (with a lot of detail) why you can NOT easily move from graphite to diamond.  The short answer is that even though they have similar atomic/molecular energy states and organization, the energy of reaction to transition from one to the other is huge, and cannot be reduced.  

Okay gottit - thanks for the explanation