ACS News Service Weekly PressPac: March 28, 2007

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Sugar shows promise in laboratory studies as a environmentally-friendly, economical alternative for reducing the toxicity of chromium waste products from the plating, mining and leather industries, according to a report by scientists in the United States and Mexico.

Chromium is normally converted to a less toxic form by treating industrial wastewater with large amounts of acid, which can foul lakes and rivers. In the current study, Bryan Bilyeu and colleagues showed that they could achieve a similar reduction in toxicity, up to 94 percent, by using natural sugars like fructose and sucrose.

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With hydrogen emerging as the most promising energy sources for fuel cells, scientists in Illinois are reporting progress toward overcoming a major barrier to tapping hydrogen’s potential as a clean, abundant energy source.

Jose Rodriguez and colleagues explain that a major problem facing today’s most promising fuel-cell technologies is that the same hydrogen-rich materials feeding the reaction often contain carbon monoxide (CO), which is formed during hydrogen production. CO “poisons,” or inactivates, the expensive platinum catalysts that convert hydrogen into electricity, reducing efficiency over time and requiring replacement.

“We’re trying to find a catalyst that achieves two things — produces hydrogen while removing a large amount of CO,” Rodriguez explained. The researchers discovered that nanoparticles of either gold or copper, supported on a metal, can perform this catalytic role. In particular, they found that the greatest catalytic activity is achieved with extremely small nanoparticles – less than 4 nanometers (4 billionths of a meter) —supported on the metal cerium oxide, or ceria. “Metal nanoparticles alone are not able to do the catalysis,” Rodriguez said. “But when you put them on the ceria, you see tremendous catalytic activity.”

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Scientists in Virginia have shown for the first time that their new films, membranes and elastomers are compatible with certain organic and inorganic molecules and will adopt properties of those “guest” molecules.

Tim Long and colleagues developed a nanostructured membrane last year that incorporates DNA base pairs. The DNA imparts molecular recognition and binding ability to the synthetic material.

With the guest molecules widely dispersed throughout the membrane, it then takes on the properties of the guest molecules. “For example,” said Long, “if the guest molecules have ionic sites (sites with positive and negative charges), you will be able to transfer water through a film because you would have ion channels at the nanoscale. It’s similar to the way a cell membrane works to control the flow of specific ions into a cell. You can create protective clothing — against chemicals — that would still allow water vapor through.”

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In 1989, ‘cold fusion’ was hailed as a scientific breakthrough with the potential to solve the world’s energy problems by providing a virtually unlimited energy source. But subsequent experiments largely failed to replicate the initial findings and the controversial concept was dismissed by most people in the scientific community.

“Although ‘cold fusion’ is considered controversial, the scientific process demands of us to keep an open mind and examine the new results once every few years,” says Gopal Coimbatore, program chair of the American Chemical Society’s Division of Environmental Chemistry, which organized this symposium.

Some researchers say they have new evidence that the phenomena — now called ‘low energy nuclear reactions’ — has evolved and is supported by rigorous, repeatable experimental data. Nearly a dozen scientists will present their findings during a daylong symposium, “New Energy Technology.”

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Some scientists dismissed the original 1989 cold fusion experiments by Stanley Pons and Martin Fleischmann as “bad” science due to alleged errors in calorimetric systems, or heat measurement that could have led to erroneous reports that the excess heat produced was nuclear in origin.

Using more precise calorimetric techniques, a new study by Fleischmann and colleague Melvin Miles reports evidence that the excess heat generated is nuclear and not the result of calorimetric errors. “Our work shows that cold fusion effects are real, but we cannot assess if this excess heat can become useful. Much more research work is needed to answer such questions,” says co-author Miles.

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