Cheap way to generate hydrogen

[PlatinumZealot]

https://pubs.acs.org/doi/10.1021/acsanm.1c04331

Videos at the bottom of the linked web page

Aluminum Nanoparticles from a Ga–Al Composite for Water Splitting and Hydrogen Generation
Gabriella Amberchan, Isai Lopez, Beatriz Ehlke, Jeremy Barnett, Neo Y. Bao, A’Lester Allen, Bakthan Singaram*, and Scott R. J. Oliver*

We report the use of a gallium (Ga)-rich aluminum (Al) composite to enhance the formation of Al nanoparticles and to facilitate its ability to split water to generate hydrogen at ambient conditions. The synthesis of this Ga–Al composite occurs without the need of an inert atmosphere or mechanical aid. Commercial Al can be used, including postconsumer aluminum foil that is usually discarded. Characterization of the Ga–Al composite with scanning electron microscopy, energy-dispersive X-ray spectroscopy, and powder X-ray diffraction illustrates that the Ga acts to dissolve the aluminum oxide coating of the Al nanoparticles. The pristine nanoparticles are then available for continuous water splitting and on-demand hydrogen generation through the Grotthuss mechanism. The water-splitting reaction does not require an applied potential and functions at ambient conditions and neutral pH to rapidly generate 130 mL (5.4 mmol) of hydrogen per gram of alloy. Any available source of water can be used including wastewater, commercial beverages, or even ocean water, with no generation of chlorine gas, as confirmed by gas chromatography–mass spectrometry. In addition, Ga remains intact, allowing it to be collected and reused indefinitely. The Ga–Al alloy is stable under cyclohexane for at least 3 months so it can be preprepared for a later use. As an initial example of the application of evolved hydrogen, we show a hydrogenation reaction

This will have big implications for formula 1.

[Rodak]

And these implications are what, exactly? Run some simple numbers re energy density of hydrogen vs petrol (or any other suitable liquid hydrocarbon fuel) and it's obvious cryogenic hydrogen is not a suitable fuel for F1; gaseous is even worse. A quick calculation shows 172 g/mole ± of aluminum is required to produce 22.4 L of hydrogen @ STP. I leave you to carry on the calculations and show how this has useful implications. Please include the electrical energy required to produce aluminum.

[Tommy Cookers]

.... the electrical energy required to produce aluminum.

isn't the appropriate measure the energy required to reprocess 'spent' Al into 'spendable' Al ?

[Rodak]

Maybe. It depends on what percentage is actually recycled and whether using the recycled aluminum to generate hydrogen forces new production for other uses.

[PlatinumZealot]

And these implications are what, exactly? Run some simple numbers re energy density of hydrogen vs petrol (or any other suitable liquid hydrocarbon fuel) and it's obvious cryogenic hydrogen is not a suitable fuel for F1; gaseous is even worse. A quick calculation shows 172 g/mole ± of aluminum is required to produce 22.4 L of hydrogen @ STP. I leave you to carry on the calculations and show how this has useful implications. Please include the electrical energy required to produce aluminum.

The process can use wasted aluminum such as that from kitchen foil and scrap metal.
The gallium dissolved the oxide layer they say, I am wondering if the can use raw alumina for this.

The abstract did not say whether the aluminum is consumed as an eltrode or not. It does say the the process is water splitting enhanced by the Grotthus mechanism.

Water splitting doesn't seem to consume metal according to Wikipedia:

Water splitting is the chemical reaction in which water is broken down into oxygen and hydrogen:

Diagram of the chemical equation of the electrolysis of water, a form of water splitting.

2 H2O → 2 H2 + O2

Efficient and economical water splitting would be a technological breakthrough that could underpin a hydrogen economy, based on green hydrogen. A version of water splitting occurs in photosynthesis, but hydrogen is not produced. The reverse of water splitting is the basis of the hydrogen fuel cell.

[Rodak]

Sure, use trash aluminum. Using rough numbers, a US size 49 compressed gas cylinder (55" high X 9" diameter) @ 2400 psi has a storage volume of about 7800 L. Using 150 g/mole of aluminum to produce hydrogen suggests it would take about 5000 grams, 5 kg, of aluminum to generate enough hydrogen to fill one cylinder. That's collecting a lot of waste foil......

The energy to split the water molecule has to come from somewhere and would require the same energy produced from combining oxygen and hydrogen in a fuel cell, assuming 100% efficiency.

[Big Tea]

It is also in this article here written in a more flowing explanation.

https://news.mit.edu/2021/using-aluminu ... -fuel-0812

I would say it defiantly has potential as it requires no (?) outside power and it does not need pure or charged water, and the water can be recovered easily. It could be very useful.

(why do I hear my Dad saying 'if something seems to good to be true, it always is? could the below be it?)

The article contains this passage ...scrap aluminum is not an easy starting material. It typically occurs in an alloyed form, meaning that it contains other elements that are added to change the properties or characteristics of the aluminum for different uses. For example, adding magnesium increases strength and corrosion-resistance.

[Ringleheim]

F1 is in the entertainment business; always has been.

The sooner they embrace that and go back to what fans want to see, the better off they will be.

Trying to establish some type of link between real world power solutions and what an F1 car runs is kind of idiotic.

I do think the long term solution for road cars is hydrogen.

[Rodak]

I do think the long term solution for road cars is hydrogen.

And why, exactly, with numbers, do you think that? Please explain fuel density, tankage, handling, et al. Please expostulate re production of hydrogen, an analysis of converting natural gas to hydrogen via the steam process using methane from gas wells or, if you prefer, electrolysis of water and how the electricity to do this will be generated, as well as the efficiencies of that process. Batteries might be better for road cars.

[PlatinumZealot]

I also say Hydrogen is the future. The "entropy" of the universe will lead us to using hydrogen as our main power source at some point becauae it is the most abundant element in the Universe. So the more we understand it the better for us whether or not is is road relevent at this moment.

This is from a very high level view of course.

[Big Tea]

This is interesting, but jump to about 2.20 and it goes off on a tangent soon after

https://www.youtube.com/watch?v=3ZKbyXCrTG8

[Mattchu]

I personally don`t see Hydrogen being an applicable energy source for use in everyday vehicles for a long time! The process to make the H² is still pretty costly and the transportation and storage just isn`t anywhere, I think the first liquid cooled H² tanker is only in the testing phase.

Also the fact it`s is highly explosive...It would seem the "buzz" is for Hydrogen at the moment but the practicalities are a long way off!

[taperoo2k]

F1 is in the entertainment business; always has been.

The sooner they embrace that and go back to what fans want to see, the better off they will be.

F1 is about the future and finding ways to go faster. The only thing that should matter in F1 is the racing and the speed. As much as I like the scream of a V8 or V10, that noise is wasted energy. Energy better used in making the cars go quicker.

Trying to establish some type of link between real world power solutions and what an F1 car runs is kind of idiotic.

If you want the big manufacturers to continue in F1, then it has to show it's relevance to the technologies that are useful in the real world. Hence the move to E10 fuels. Eventually I expect the fuel will be mostly Ethanol with little to no oil based products in the fuel. If it doesn't work out, then Hydrogen is possibly the next logical step.

Or if they ever get algae produced oil to a point where it's cost effective, then that might be another option for F1.

I do think the long term solution for road cars is hydrogen.

We are going to need battery electric and Hydrogen fuel cells for different applications. Hydrogen for long distances and battery electric for shorter distances.

Anyway whoever manages to crack the problem of producing carbon neutral hydrogen at a low price point will
be rolling in cash. As for Hydrogen itself ? It's unlikely to explode.

[Rodak]

Big Tea, good article, thanks.

The abstract did not say whether the aluminum is consumed as an eltrode or not. It does say the the process is water splitting enhanced by the Grotthus mechanism.

The aluminum is converted to aluminum oxide, alumina. The is actually what is extracted from bauxite ore to produce the metal. Unfortunately alumina has to go through a reduction cell to produce the metal and this is where very large amounts of electricity are consumed. Bottom line, the alumina waste from generating hydrogen would require processing to be returned to its metallic state and be reused; not a very eco friendly process and a net energy loss. It might be more efficient to use electrolysis to make hydrogen.....

As I described in an earlier post, about 5 kg of aluminum would be consumed to produce 7500 L of hydrogen gas and then you would be sitting on about 5 kg of alumina waste requiring electricity for smelting to aluminum metal so it could be reused.

Edited to add: Essentially what is happening here is the electrical energy originally used to convert alumina is recovered by converting the aluminum to alumina and that energy dissociates hydrogen from the water molecules. An interesting circle, but no free lunch.....

[Tommy Cookers]

Big Tea, good article, thanks.

.....about 5 kg of aluminum would be consumed to produce 7500 L of hydrogen gas .....

about 5 kg of aluminium and some kg of water would be consumed .....
maybe ok to live-feed a fuel cell giving 70% efficient drive downstream
(hydrogen having far more heat per kg than does a liquid fuel)

aluminium (and some other metals) eg in caustic soda solution also splits water
perhaps 'they' should use a metal with a much smaller atomic weight ? - maybe lithium ?

though splitting water to extract hydrogen from water also produces oxygen
and aluminium isn't the worst fuel ever for a heat engine

this could result in a hybrid hybrid vehicle - or even a hybrid hybrid hybrid ?
can of worms anyone ?