Enzymes Could Convert Chemicals to Energy

Many people are beginning to realize that global warming is not going to go away by itself, as engines that burn gasoline emit pollutants, such as carbon dioxide, that cause global warming. The US Department of Energy is very interested in a new proposition that involves using enzyme emulations to transform chemicals into energy.

To study the new applications, the Pacific Northwest National Laboratory received $1.98 million over the next three years. This technique will try to reproduce nature's way of doing things in order to create an economically feasible way to produce clean energy using fuel cells.

"This is a basic research project, but one that we hope will provide new knowledge that will be pertinent to the production of hydrogen or oxidation of hydrogen in fuel cells," said Morris Bullock, co-leading the project with Dan DuBois, both working for the PNNL.

Called an "electrocatalytic reaction" the new method aims to produce energy via catalytic oxidation of hydrogen in fuel cells, a method considered "very attractive for many applications," according to Bullock.

Previous chemical conversions using this technique have been developed, but so far they proved too expensive, as the fuel cells need a precious metal, platinum, for the catalytic reactions. "We seek to prepare new metal complexes based on abundant, inexpensive metals such as iron, manganese and molybdenum," added Bullock.

The scientists want to examine natural systems, like those commonly found in species of bacteria and algae that enlist hydrogenase enzymes in energy production. They hope "to replicate the function but not the exact structure" of the natural enzymes in commercial applications.

Enzymes from these microorganisms have been studied and have shown that sites where electrocatalysis takes place contain nuclei made up of iron-iron or nickel-iron complexes.

Similarly, synthetic catalysts based on inexpensive metals that emulate the high catalytic activity of the enzymes could replace platinum, of the most expensive precious metals found in nature.