How US Army Research Laboratory made nano-aluminium alloy that produces Hydrogen from Water

Hydrogen is the fuel of the future. But to produce Hydrogen has required Electrolysis, which means power, be it from fossil fuels or Solar power, has to be used to make Hydrogen, adding to the cost of this wonder fuel.

So it's quite interesting to note the discovery by US Army Research Laboratory at Aberdeen Proving Ground, Maryland in January 2017 of an aluminium alloy that reacts with water and produces Hydrogen gas as reported in the article “Nano aluminium offers fuel cells on demand – just add water”, published 3 August 2017, By David Hambling, New Scientist. 

The discovery was made by US Army Research Laboratory at Aberdeen Proving Ground, Maryland while testing a new, high-strength aluminium alloy. When water was added to the material during routine testing, it started bubbleing and gave of a gas. This gas proved to be Hydrogen.

The accidental discovery of what is effectively a Hydrogen-producing metal catalyst in the form of this aluminium alloy may be the first step to reviving the struggling hydrogen economy as pointed out in my blog article entitled “Whither the Hydrogen Economy for Jamaica”.

It could potentially make Hydrogen Fuel cells portable, providing an alternative to Li-Ion batteries and liquid fuels. For us Jamaicans is could mean Hydrogen replacing LPG Cooking Gas by improving on the research done by UTECH as noted in my blog article entitled “UTECH and Hydrogen as Cooking Gas – How Hydride Salts make Hydrogen Cooking Gas and Fuel Cells possible”. 

So how did the US Army Research Laboratory make this aluiminium alloy?

US Army Research Laboratory and Hydrogen - Aluminium Alloy Just a Bubble with Hydrogen

First thing for my chemistry students, aluminum doesn't normally react like this.

It usually reacts in the presence of Oxygen to produce an oxide coat that prevents further reaction as follows:

Al_(s) + O_2(g) → Al₂O_3(s)

When aluminium powder is reacted with water it also liberates Hydrogen from Water, producing Aluminum Hydroxide Al₂(OH)₆ as a byproduct.

2Al_(s) + 6H₂O_(l) → Al₂(OH)_6(s) + 3H_2(g)

Good to note that aluminum doesn’t react readily with water due to its protective oxide coat; energy, such as via heating with a Bunsen burner, has to be added to coax the reaction to occur.

Also the use of a proton donor, such as an acid or a base, a proton acceptor, can be used to accelerate the reaction, as pointed out in the video below.

However, a third method, not often discussed in most chemistry classes, involves increasing the surface area of the aluminium and breaking up the protective oxide coat. By simply making the

 Aluminium into a powdered nanomaterial via special milling processes, you can increase the surface area of the aluminium to make it more reactive i.e. powdered or so-called nanoparticles of aluminium.

Good to note too that Hydrogen gas does evolve (He, Hu, Kang, Li and Zeng, 2013) during the extraction of Aluminium from molten Aluminium Oxide via electrolysis, though Hydrogen gas is treated more as a problem than a solution.

This alloy differs from these examples above as instead of forming a stable oxide or salt that halts the reaction, it just kept reacting. 

But the reasons are similar; the aluminium in that case is alloyed with other impurities and due to the high temperature, is very reactive. Moreover, the aluminium and its impurities become arranged in regular crystalline patterns thanks to electron flow due to the electrolysis process.

This is the case also with the aluminium alloy US Army Research Laboratory; it’s fused with one or more other metals arranged in a particular nanostructure in a regular pattern, resembling salt crystals.

This is different from how most metals are composed, which is usually of metal cations surrounded by a sea of electrons, with the metal cations randomly arranged. In this case, the aluminum and the other metal making up the alloy are arranged in a lattice structure similar to graphite, thus resulting in each aluminum atom being surrounded by no more than three other metal atoms.

The result is a nano-structure that is continuously reactive to water, as it doesn’t permanently bind to Oxygen, the original intent of the US Army Research Laboratory; a light weight rust proof aluminium alloy. Adding water to this aluminium in such a highly reactive state results in aluminium oxide or hydroxide and hydrogen.

Clearly, you can see where this is going; Hydrogen Fuel cells and Batteries that last forever.

Nano-particles of aluminium - Practical Fuel Cells and a Solution to the Hydrogen Economy

This folks, is basically nano-particles of aluminium in a fixed crystalline lattice structure acting as a catalyst to produce hydrogen.

In my book, this is a big improvement on using Iron and Nickel Oxide electrodes for electrolysis as explained in my blog article entitled “@Stanford University Nickel-Iron Electrolysis Electrodes – How Oxides of Iron and Nickel herald Cheaper Electrodes All-Electric Vehicle”
, as the battery has been eliminated from the equation.

Not only that, Water and aluminium are easy to transport and the reaction occurs at room temperature and is 100% efficient as confirmed by team leader for the US Army Research Laboratory Scott Grendahl, quote: “Ours does it to nearly 100 per cent efficiency in less than 3 minutes”.

This means Hydrogen Fuel cells can be designed without having to use Hydride salt to store Hydrogen as explained in my blog article entitled  “Apple files patent for Hydrogen Fuel cell – Why Portable Hydrogen Fuel Cells needed to cut the Analog Power Cord”. 

This process can produce hydrogen as needed. A solution to the transportation problem that has hampered the developement of the Hydrogen Economy, to quote physicist Anit Giri: “The problem with hydrogen is always transportation and pressurisation”.

This may be the miracle breakthrough needed in the Battery tech world as noted by Anthony Kucernak, a fuel cells researcher at Imperial College London, quote: “The important aspect of the approach is that it lets you make very compact systems. That would be very useful for systems which need to be very light or operate for long periods on hydrogen, where the use of hydrogen stored in a cylinder is prohibitive.”

Batteries lighter than the current Li-Ion and with higher power densities is possible, remaining stable for longer periods of time. Best of all, it could be used as a mean of recycling aluminium, as the nano-structure aluminium alloy can be made from scrap aluminium.

References

He H, Hu Z., Kang M., Li D, Zeng, J. (October 2013). Nanostructure of aluminum oxide inclusion and formation of hydrogen bubbles in molten aluminum. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/24245169