In research published in the journal Angewandte Chemie, and featured in Nature and Chemistry World, they studied materials that have a porous sponge-like structure in which to store hydrogen — and found that bigger is not necessarily better. Bigger pores, they found, don't necessarily store the most hydrogen fuel.
The work gives a boost to attempts to cram hydrogen into a small space so that it can be used practically as a fuel. Fuel cells, which run on hydrogen and oxygen, are a potentially environmentally friendly way to power vehicles, producing only water as a waste product.
But hydrogen fuel needs to overcome a number of stumbling blocks before it can replace our oil-based economy. Not the least of these is how to safely store enough hydrogen fuel for cars to cover a reasonable distance before their supplies must be replenished.
One possible solution is to pack hydrogen into porous materials, which soak up the gas like a sponge. Professor Martin Schröder and his colleagues, Professor Neil Champness and Dr Hubberstey from the School of Chemistry, with Dr Gavin Walker from the School of Mechanical, Materials and Manufacturing Engineering at The University of Nottingham, have been investigating so-called metal organic frameworks (MOFs) — molecular scaffolding filled with tiny cylindrical pores that hydrogen gas can be forced into.
Professor Schröder said: "The idea up to this point has been to increase the pore volume, so as to fit in more gas."
That makes intuitive sense: the bigger the cylinders, the more their capacity, and the greater the inside surface area available for hydrogen to attach to. But now the painstaking University of Nottingham study has quantified the amount of hydrogen that can be put into three MOFs made of identical material but with different pore sizes. Surprisingly, the study showed that the middle-sized pores could hold the highest density of hydrogen.
Professor Schröder added: "In a very small tube, the hydrogen gas molecules all see the wall and interact with it. But in a larger tube, the molecules see less of the wall and more of each other: that interaction is weaker, so they don't pack together as closely."
The researchers conclude that there is an optimum pore size for any given material.
The US Department of Energy (DoE) has set a series of advisable targets that a hydrogen-fuelled vehicle should meet in order to be economically viable: by 2010, the storage system's capacity will need to be greater than six per cent hydrogen by weight, for example.
Schröder's team shows that their frameworks reach this requirement, and come close to the DoE's volume-density target of 45 grams per litre. In fact they have achieved the highest percentage hydrogen uptake of any such material thus far reported.
He added: "MOFs appear to be a viable alternative technology to other materials currently being investigated for hydrogen storage since they can show excellent reversible uptake-release characteristics and appropriate capacities."
Emma Thorne | alfa
3D scans for the automotive industry
16.01.2017 | Julius-Maximilians-Universität Würzburg
Improvement of the operating range and increasing of the reliability of integrated circuits
09.11.2016 | Technologie Lizenz-Büro (TLB) der Baden-Württembergischen Hochschulen GmbH
An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.
Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...
Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.
Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...
Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.
As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...
Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.
With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...
Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine
Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...
19.06.2017 | Event News
13.06.2017 | Event News
13.06.2017 | Event News
26.06.2017 | Life Sciences
26.06.2017 | Physics and Astronomy
26.06.2017 | Information Technology