Revealing new applications for carbon nanomaterials in hydrogen storage
March 12, 2009An international research team, involving Professor Rajeev Ahuja at Uppsala University and researchers in the USA, set out to understand the mechanism behind the catalytic effects of carbon nanomaterials. Experimental and theoretical efforts were combined in a synergistic approach and the results, published this week in the ASAP section of the journal Nano Letters, will fasten efforts to develop new catalysts.
Our energy-hungry world has become increasingly dependent on new methods to store and convert energy for new, environmentally friendly modes of transportation and electrical energy generation as well as for portable electronics. Mobility — the transport of people and goods — is a socioeconomic reality that will surely increase in the coming years. Hydrogen, which can be produced with little or no harmful emissions, has been projected as a long term solution for a secure energy future. Research into safe and efficient means of hydrogen production, storage, and use is essential to make the "hydrogen economy" a reality.
Car manufactures are showing interest in using solid state hydrogen storage materials, e.g. NaAlH4, as new energy storage media. The functional properties of these materials however have to be improved by catalysts. The effect of earlier catalysts, e.g. Ti, has been difficult to explain. The current results give an unambiguous understanding of the mechanism at work in the new carbon nanomaterial catalysts.
The researchers set out to understand the mechanism behind the catalytic effects of carbon nanomaterials, specifically on the example of sodium alanate, which is a popular material for hydrogen storage studies.
"Now that the catalytic capabilities of carbon nanomaterials have been demonstrated so clearly and the mechanism that makes this behaviour possible has been understood, we expect a strong impulse on putting this effect to use in practical applications.", says Professor Rajeev Ahuja.
"Certainly, our findings have the strongest impact in the field of hydrogen storage, but beyond that, the same mechanism that we revealed can make carbon nanomaterials a very important catalyst in many other systems as well."
The extensive simulations were performed at Uppsala University's Multidisciplinary Center for Advanced Computational Science (UPPMAX).
Source: Uppsala University
Jun 16, 2008 |
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"Hydrogen, which can be produced with little or no harmful emissions"
This is simply untrue.
Production of hydrogen from methane requires energy input and produces CO2.
Production of hydrogen from water requires energy input to split water into hydrogen and oxygen.
Where does this energy come from that produces no harmful emissions?
If we have a source of clean energy, why would we waste half of it in the production of hydrogen.
To be useful, the hydrogen would need to be oxidized either by a fuel cell or a combustion engine. Niether of which is more than 50% efficient.
Hydrogen is simply a carrier of energy, like a power line. You still need a source of energy in the first place.
But the point is really not absolutely clean.
Every taking produces waste. What you need is a system that gives more than it takes, the modern word for which is "sustainable." We just need a system that can provide what we need at a pace that enables the system to recover faster than we can consume.
f(x)=X
"f(x)=X<Y
It is also in this sense that one should assess the phrases "minimize waste," "reduced waste," or "zero waste."
@tpb: Today, this is indeed still incorrect (for example when it comes to production of hydrogen from methane). But producing hydrogen from water using solar energy could in principle be clean and sustainable. Then hydrogen will store and carry that energy, for times when it's "cloudy" and for mobile applications.