Nanotechnology could promote hydrogen economy

March 29, 2005

Say "nanotechnology" and people are likely to think of micro machines or zippy computer chips. But in a new twist, Rutgers scientists are using nanotechnology in chemical reactions that could provide hydrogen for tomorrow's fuel-cell powered clean energy vehicles.
In a paper to be published April 20 in the Journal of the American Chemical Society, researchers at Rutgers, The State University of New Jersey, describe how they make a finely textured surface of the metal iridium that can be used to extract hydrogen from ammonia, then captured and fed to a fuel cell. The metal's unique surface consists of millions of pyramids with facets as tiny as five nanometers (five billionths of a meter) across, onto which ammonia molecules can nestle like matching puzzle pieces. This sets up the molecules to undergo complete and efficient decomposition.

"The nanostructured surfaces we're examining are model catalysts," said Ted Madey, State of New Jersey professor of surface science in the physics department at Rutgers. "They also have the potential to catalyze chemical reactions for the chemical and pharmaceutical industries."

A major obstacle to establishing the "hydrogen economy" is the safe and cost-effective storage and transport of hydrogen fuel. The newly discovered process could contribute to the solution of this problem. Handling hydrogen in its native form, as a light and highly flammable gas, poses daunting engineering challenges and would require building a new fuel distribution infrastructure from scratch.

By using established processes to bind hydrogen with atmospheric nitrogen into ammonia molecules (which are simply one atom of nitrogen and three atoms of hydrogen), the resulting liquid could be handled much like today's gasoline and diesel fuel. Then using nanostructured catalysts based on the one being developed at Rutgers, pure hydrogen could be extracted under the vehicle's hood on demand, as needed by the fuel cell, and the remaining nitrogen harmlessly released back into the atmosphere. The carbon-free nature of ammonia would also make the fuel cell catalyst less susceptible to deactivation.

When developing industrial catalysts, scientists and engineers have traditionally focused on how fast they could drive a chemical reaction. In such situations, however, catalysts often drive more than one reaction, yielding unwanted byproducts that have to be separated out. Also, traditional catalysts sometimes lose strength in the reaction process. Madey says that these problems could be minimized by tailoring nanostructured metal surfaces on supported industrial catalysts, making new forms of catalysts that are more robust and selective.

In the journal article, Madey and postdoctoral research fellow Wenhua Chen and physics graduate student Ivan Ermanoski describe how a flat surface of iridium heated in the presence of oxygen changes its shape to make uniform arrays of nanosized pyramids. The structures arise when atomic forces from the adjacent oxygen atoms pull metal atoms into a more tightly ordered crystalline state at temperatures above 300 degrees Celsius (or approximately 600 degrees Fahrenheit). Different annealing temperatures create different sized facets, which affect how well the iridium catalyzes ammonia decomposition. The researchers are performing additional studies to characterize the process more completely.

Source: Rutgers, the State University of New Jersey

Explore further: New process produces hydrogen at much lower temperature

Related Stories

New process produces hydrogen at much lower temperature

December 1, 2016

Waseda University researchers have developed a new method for producing hydrogen that is fast, irreversible, and takes place at much lower temperatures using less energy. This innovation is expected to contribute to the spread ...

Turning greenhouse gas into gasoline

November 15, 2016

A new catalyst material developed by chemists at MIT provides key insight into the design requirements for producing liquid fuels from carbon dioxide, the leading component of greenhouse gas emissions. The findings suggest ...

Chemistry driven by the sun, for a sustainable future

November 8, 2016

A group of European chemists including Prof. Joost Reek of the University of Amsterdam's research priority area Sustainable Chemistry has recently published a whitepaper on Solar-Driven Chemistry. They show that it is possible, ...

Recommended for you

Swiss firm acquires Mars One private project

December 2, 2016

A British-Dutch project aiming to send an unmanned mission to Mars by 2018 announced Friday that the shareholders of a Swiss financial services company have agreed a takeover bid.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.