Scientists at the Tokyo University of Science have used rust as a catalyst in light-assisted hydrogen production from organic waste, finding it produces 25 times more hydrogen than previous titanium dioxide catalysts.
Japan and Korea, in particular, see hydrogen as the clean fuel of the future, and are reorganizing themselves to make way for a zero-emissions "hydrogen economy" in which transport will mainly be driven by fuel cell vehicles and hydrogen-burning engines, which emit only water as their end product.
Economical and sustainable hydrogen production methods, however, have not really been nailed down. Electrolysis wastes a lot of energy and uses up fresh water. Gas or coal production releases large amounts of carbon at the production site, negating any perceived environmental benefits. Solar-driven photocatalytic processes invented in the 1970s produce so little hydrogen they're not worth the trouble or expense of their titanium dioxide catalysts.
Now, a team from the Tokyo University of Science believes it's found a solution for cheap, highly efficient photocatalytic hydrogen production based on a special type of rust.
Using the light from a mercury/xenon lamp, a water-methanol solution and a form of rust called α-FeOOH as the catalyst, the team found themselves producing 25 times more hydrogen than previous titanium dioxide techniques. As an added benefit, something about this particular form of rust seems to help stop the hydrogen gas from re-coupling with the oxygen in the container, allowing easier separation and heading off a potentially explosive hazard. The configuration continued producing hydrogen in a stable fashion for more than 400 hours.
The team next plans to study exactly what role oxygen plays in activating light-induced α-FeOOH reactions, because it stopped working altogether when the oxygen was removed from the reaction chamber. While this technique still requires the splitting of water – far from an infinite resource – to create hydrogen, it could be an efficient way of doing so using sunlight without requiring any expensive catalysts.
The study was published in Chemistry: A European Journal.
Source: Tokyo University of Science
How much energy is used to power the artificial light that is needed for this increased rate of reaction to take place? What is the cost of that portion of the system? What is the rate of amortization of it? Or do all of those extra things come cheaply because they all grow on trees found in Nature?
Randy
Hydrogen remains a diatomic gas which is both highly explosive and extremely difficult to seal, being the smallest molecule in existence. The tank has to be extremely high performance, holding thousands of PSI, as compared to tires which only hold about 30 psi. The problem of acetylene was solved by dissolving it in acetone and stabilizing it in a porous structure, but there is still no equivalent safe storage method for hydrogen. Plus no matter what you can't get past the potential of hydrogen to be misused as a bomb. I think ethanol still makes more sense, it's produced sustainably (no net contribution to atmospheric CO2) and burns with high equivalent octane and the resultant combustion is very gentle on internal combustion engines.
I also agree with Expanded Viewpoint that this is a very poorly written article, and it makes me wonder about New Atlas.