Making Hydrogen Fuel Even Greener

Hydrogen has shown much promise as a green fuel. Pim Frederix investigates how the production of hydrogen can become even more environmentally friendly.

Since humanity realised it cannot keep using our quickly depleting supply of fossil fuels, researchers have been frantically searching for alternatives. Hydrogen (H2) is attracting more and more attention as a more sustainable fuel (especially useful in cars). H2 is a clean fuel since its only combustion product is water, rather than greenhouse gases and soot, and would therefore be a good replacement. The energy needed for the production of hydrogen gas can often be drawn from renewable sources like wind and solar power, making it even more attractive. However, the current method for converting hydrogen into energy relies on heavy metal (like platinum) fuel cells, which are environmentally unfriendly, expensive and relatively inefficient. This therefore limits the potential exploitation of H2. Moreover, most hydrogen is produced by steam reforming, which still requires fossil fuels (mostly methane). This has prompted the research groups of Rein Ulijn (Department of Chemistry) and Neil Hunt (Department of Physics) at the University of Strathclyde to look into the use of alternative systems to improve the production and harvesting of hydrogen.

Searching for catalysts

The development of catalysts is a very important research theme within chemistry. Its goal is to lower the energy required for a reaction to proceed so that less heat or electricity is needed to form the products. An ideal situation for hydrogen is depicted below; with a catalyst (blue line) H2 can be formed without crossing the high energy barrier in the reaction progress. To achieve this in practice, scientists have once again drawn inspiration from nature. In the late 1990’s a type of bacteria was discovered near oceanic volcanoes which was found to produce hydrogen using its own microscopic hydrogen fuel cell. The enzyme responsible for the conversion of the hydrogen (called hydrogenase) has been isolated and can be modelled by a small molecule with two iron atoms. These model systems have already shown that they can produce hydrogen on a small scale [1], but they are generally unstable in the presence of water, light and oxygen (which are typically quite abundant substances). Moreover, their production rate is often insufficient for commercial applications.



Finding solutions

One way to approach the current problems with the hydrogenase models is to vary the functional groups around the iron atoms in the model or to even replace the iron with a different metal like nickel. Very recently, a US research group has demonstrated that they could surpass the catalytic rate of the native enzyme by a factor of 10, producing 100,000 molecules of hydrogen per second per catalyst molecule [2]. At the University of Strathclyde, researchers have shown that you can further improve the stability and catalytic rate of existing catalysts by encapsulating them in a biomaterial. These materials have a gel-like nature, as shown in the title picture, comprised of short peptides in water. They are cheap, biocompatible and biodegradable with properties that can easily be modified [3]. Using these materials, the hydrogenase mimic was much less sensitive to light. They also showed that in the gel it was stable for up to two weeks in an environment of 90% water, while it was completely insoluble in pure water. Water is crucial for hydrogen production; it is a good transporter or source of protons, the starting material in the formation of hydrogen, so that the catalytic rate of the model generally shoots up at least one order of magnitude in the presence of water. Moreover, confining a catalyst to an immobile pocket (the stiff gel material) is generally beneficial for the amount of H2 produced per second. These results will contribute to a cleaner and more efficient way of making the hydrogen needed for the next generation of energy consumers.

Tell your friends!Share on Facebook0Tweet about this on Twitter0Share on Google+0Share on LinkedIn0
Discuss

Author

// Pim Frederix is a PhD student in the Departments of Physics and Chemistry at the University of Strathclyde.

Creative Commons License Making Hydrogen Fuel Even Greener by Pim Frederix is licensed under a Creative Commons Attribution 3.0 Unported License.


Other Articles

Mini-Neptunes, Super-Earths and the Search for Extrasolar Planets

There are a few ways to create a habitable planet. We think the way Earth was created was as a bunch of rocks that were orbiting the Sun and all clumped together. Scientists think that later extra water was brought by asteroids. However as the search for extra-solar planets progresses we find more and more … More


Science Ceilidh at the Glasgow Science Centre

Friends of theGIST Glasgow ScienceGRRL are proud to announce that they will be hosting a Science Ceilidh at the Glasgow Science Centre on Saturday 7th March to celebrate International Women’s Day! The event will include science based ceilidh dances – with names such as Orcadian Strip the Double Helix and the Dashing White Blood Cell. … More


Attractiveness Can Make You Quicker (If You Are a Website)

New operating systems often look more “flash” than the previous iteration, with many an Apple/Android fan raving to their friends about the new look, but do improved aesthetics actually make the product better? According to new research by Irene Reppa of Swansea University and Siné McDougall of Bournemouth University, the answer is yes . By … More


Electric vehicles – driving us forward to a greener future

5 February 2015 Many renewable energy sources are now working remarkably efficiently and many scientists feel that with sufficient financing, continuing research and real dedication from world leaders that these could eventually take over from fossil fuels entirely. For example, in 2010, Alec Salmond claimed that Scotland could soon be run entirely on green energy … More


Discussion

Leave a Reply

Your email address will not be published. Fields marked with an * are required. By commenting you consent to us placing cookies on your computer.





You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>