Scientists have developed catalysts that harness the ability of hydrogen peroxide to break down a variety of harmful agents, ranging from sulfur in diesel fuel to an anthrax-like bacterium. What is more, the process was developed under the tenets of Green Chemistry, which means it is sustainable and environmentally friendly. Researchers reported on the work yesterday at a national meeting of the American Chemical Society in New York City.

Terry Collins of Carnegie Mellon University led the team that developed the new class of catalysts, which are known as TAML^R-activators. In general, these compounds increase the ability of hydrogen peroxide to break down other substances through a process called oxidation. By adjusting the reaction conditions, the researchers have shown that these molecules can attack a variety of pollutants. For example, Colin Horwitz, also at Carnegie Mellon, described experiments that indicate the catalysts can remove up to 85 percent of sulfur compounds present in automotive fuels. Diesel fuel in the U.S currently contains about 500 parts per million of sulfur contaminants, which are associated with both asthma and acid rain, and degrade fuel efficiency. "We are working to develop Fe-TAML activators to clean fuel to the point where they will comply with stringent EPA sulfur standards slated to go into effect by 2006," Horwitz says. "This technology could aid significantly in the development of cleaner burning, more fuel-efficient automobile engines."

The catalytic oxidation process can also work against water-borne pathogens. A third team member, Deboshri Banerjee, reported that in laboratory tests it killed 99.999 percent of cultured spores of Bacillus atrophaeus, which is often used in tests to simulate the more dangerous Bacillus anthracis, or anthrax. The scientists posit that the catalyst helps the hydrogen peroxide break bonds in the outer coats of the spores, breaking them open and killing them. Because bacterial spores tend to be more resistant than other types of microorganisms, the researchers hope that their process can also be used to treat other waterborne pathogens, particularly those such as Cryptosporidium or Giardia that are prevalent in areas with poor sewage treatment. "Our single biggest goal," Collins remarks, "is to develop a system of catalysts that can eliminate a wide range of pathogens in water to have cleaner drinking water worldwide."

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