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Chevrolet Equinox fuel cell vehicle  (Source: DailyTech)
New catalyst is 2000 times more tolerant of carbon monoxide

The quest for alternative fuel sources that are cleaner, cheaper, and more abundant than traditional fossil fuels is underway around the world. Researchers are studying everything from battery power to solar energy and fuel cells.

Fuel cells hold great promise and have long been studied as alternatives to fossil fuels. Traditionally, the problems plaguing fuel cell-powered vehicles that run from hydrogen include how to produce the hydrogen cheaply and how to store it safely. Despite issues that still surround fuel cell-powered vehicles, a study conducted in June by Pike Research found that within the next decade 670,000 fuel cell powered vehicles would be sold each year.

Researchers at the Cornell University Energy Materials Center have made a breakthrough discovery that will make hydrogen fuel cell power much more economical. The breakthrough comes in the form of a new catalyst that uses platinum nanoparticles. Platinum is traditionally used in fuel cells as the catalyst, but platinum is expensive and can be easily deactivated in the presence of even low levels of carbon monoxide rendering the fuel cell inoperable.

The Cornell researchers have discovered a method of making the platinum catalyst able to withstand thousands of times more carbon monoxide. The process also makes the platinum catalyst material much cheaper to produce. The team created the catalyst using platinum nano particles that are deposited on a support material of titanium oxide. The team then added tungsten to increase the electrical conductivity of the catalyst. The resulting platinum catalyst is 2,000 times more resistant to carbon monoxide than a catalyst using pure platinum. 

That higher resistance to carbon monoxide means that the fuel cell can burn hydrogen with as much as 2% carbon monoxide in it. The researchers say this is very important because hydrogen derived from petroleum has a high concentration of carbon monoxide in it. The ability for the catalyst to withstand more carbon monoxide eliminates the need to clean the hydrogen as much, thereby reducing the cost of making hydrogen.

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RE: Hydrogen derived from hydrocarbons....
By JediJeb on 8/3/2010 2:54:32 PM , Rating: 3
One reason to use petroleum for the hydrogen source is that instead of the 30-35% efficiency you get from burning it in a normal combustion engine, I believe using it for a source of hydrogen for a fuel cell you jump up to over 60% efficiency, though I may be totally wrong. But if that is correct then it would make a lot of sense to use the petroleum in a fuel cell as you would need less of it to do the same amount of work.

RE: Hydrogen derived from hydrocarbons....
By Solandri on 8/3/2010 4:29:04 PM , Rating: 5
This is correct. Burning petroleum in a combustion engine, you're limited by the Carnot efficiency. The maximum energy you can extract is 1 - Tc/Th where Tc is the cold temperature of your heat sink (usually the air for cars), and Th is the high temperature of your engine. For most automobile applications, this puts you around 30% engine efficiency. That is, 30% of the energy in the fuel goes into doing work, the other 70% just creates waste heat.

Fuel cells bypass this by converting the energy directly to electricity instead. They can frequently achieve 60% efficiency, with some fuel cells in the lab hitting over 80% efficiency.

By Etsp on 8/4/2010 3:39:49 AM , Rating: 2
There are some caveats to that as well... That formula assumes that the cooling system itself does not produce energy. Which is true in the vast majority of cases. However, there are means to derive electrical or kinetic energy that also act to cool the engine.

Two examples would be water injection, and peltier plates. Granted, these two methods aren't used much at all, but that doesn't mean there aren't ways to improve the efficiency of an ICE beyond that temperature difference barrier. It would require innovation on the cooling systems, but it's very possible. As far as how practical this is... well, at least it's more practical than some ideas being subsidized.

"Young lady, in this house we obey the laws of thermodynamics!" -- Homer Simpson

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