Following Nature's Lead,
Scientists Seek Better Catalysts
Theoretical investigations of a bacterial enzyme by Brookhaven Lab scientists have revealed a catalytic complex with higher predicted chemical reactivity than that of industrial catalysts currently in use, sparking hope for cleaner, more efficient hydrogen production.
“We wanted to establish how the biological system works, and then compare it with materials currently used in industry for these chemical processes — and we found that the biological system is indeed better.”
Next, the scientists tested the theoretical chemical reactivity of the complex with a variety of reactants important in either the production of hydrogen or the control of air pollution. Finally, they compared those results with the reactivity of other ironsulfur-complex catalysts, including those that are currently used for these catalytic processes in industry.
“Our calculations predict that this particular unit should be four to five times more reactive than the catalysts currently used, which is very significant,” Rodriguez said. “With this structure, the key is that you have an open side of the molecule to bind things and do chemistry because it is missing one cysteine neighbor. You can make it react with other things.”
The next challenge will be to see if the scientists can use the enzyme or synthesize a mimic of its cysteine-iron-sulfur center – an engineering project on the nanoscale (i.e., measured in billionths of a meter).
“Even if we can’t use this exact enzyme, then maybe we could create other molecules or particles with this type of structure using synthetic methods,” Abreu said.
This type of work – synthesizing, studying, and fine-tuning the properties of nanoscale catalytic systems – will be a major research focus at Brookhaven Lab’s Center for Functional Nanomaterials (CFN, see sidebar), currently under construction.
“Once you have the nanoparticles, you can do the testing with the catalytic reactions,” Rodriguez said. “Then, if they work the way the theory predicts, you have something that is really useful.”
The research was funded by the Office of Basic Energy Sciences within the U.S. Department of Energy’s Office of Science. The CFN at Brookhaven Lab is one of five nanoscience research centers being constructed and funded by DOE’s Office of Science.
