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)
+ O2(g) → Al2O3(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) + 3H2(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.
, 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
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