Chemists and Biologists Make Bionic Leaf That Produces Alcohol Fuel

Scientists have merged the powers of chemistry and biology to come up with a bionic leaf that produces fuel. The results are published in Science journal.

A team of chemists led by Daniel Nocera of Harvard University, together with a team of biologists led by Pamela Silver of Harvard Medical School developed a kind of living battery, which they call a bionic leaf. The artificial photosynthetic device uses solar electricity from a photovoltaic panel to power the chemistry that splits water into oxygen and hydrogen, then adds pre-starved microbes to feed on the hydrogen and convert carbon dioxide in the air into alcohol fuels. It pumps out 216 milligrams of alcohol fuel per liter of water. However, the catalyst that enabled water-splitting chemistry possible had the side effect of poisoning the microbes.

This time the team found a better catalyst which effectively splits water and plays well with microbes. The catalyst is composed of an alloy of cobalt and phosphorus, an amalgam commonly used as anti-corrosion coating for plastic and metal parts present in almost everything like faucets and circuit boards. The new cobalt catalyst also splits water into hydrogen and oxygen without creating the kind of reactive oxygen molecules that can damage DNA or other processes essential to continuing life. 

With the use of the new catalyst, the new version of bionic leaf had boosted the efficiency at producing alcohol fuels like isopropanol and isobutanol to roughly 10 percent, which is better than the efficiency of natural photosynthesis. This new device could help mitigate planet-warming pollution concerns, at the same time bringing cleaner fuels to people who do not currently have access to modern energy. 

"I took air plus sunlight plus water and I made stuff out of it, and I did it 10 times better than nature. That makes me feel good," Nocera says.

Read the complete story in Scientific American.