artificial-'leaf'-creates-clean-gas

Researchers have found a way to create a widely-used gas currently derived from fossil fuels by using more environmentally friendly “artificial leaf” technology, they said.

A team at the University of Cambridge—led by Professor Erwin Reisner from Cambridge’s Department of Chemistry–developed the technology, which uses only sunlight, water, and carbon dioxide to create syngas, a common gas is used in fuels, pharmaceuticals, plastics, and fertilizers.

artificial leaf, University of Cambridge, syngas, pharmaceuticals, plastics, fertilizers, hydrogen, carbon monoxide

Researchers at Cambridge University have developed “artificial leaf” technology that can produce syngas, a widely-used gas currently derived from fossil fuels and used in the production of fuels, pharmaceuticals, plastics, and fertilizers. (Image source: Cambridge University)

Current methods to create this gas use a mixture of hydrogen and carbon monoxide in an industrial process that emits carbon dioxide and other pollution-causing elements into the atmosphere. The new technology, then, is a far cleaner alternative to producing this gas, said Virgil Andrei, a PhD candidate at the university who worked on the project.

“Syngas, a mixture of hydrogen and carbon monoxide, is a crucial intermediate in the industrial synthesis of conventional fuels, alcohols, and long-chain hydrocarbons,” Andrei told Design News. “In case of our technology, we only use light, water, and CO2 to obtain syngas, which is normally produced from fossil methane.”

Nature-Mimicking Design

The device developed by the team is based on photosynthesis—the process plants use to turn carbon dioxide to food, and its design also reflects this natural simplicity, he said.

“The device … uses two light absorbers without needing additional wiring,” Andrei told Design News. “In addition, we use a selective molecular catalyst instead of expensive metals for CO2 reduction, which provides an economic advantage to other electrochemical and industrial approaches.”

While scientists already have developed other artificial-leaf technologies, typically these devices produce hydrogen, not syngas. The Oxford team said they were able to achieve the latter because of the combination of materials and catalysts they used.

The technology works like this: When the device is immersed in water, one light absorber uses a catalyst made from the abundant element cobalt to produce oxygen. The other carries out the chemical reaction that reduces carbon dioxide and water into carbon monoxide and hydrogen, forming the syngas mixture.

Potential for Clean Energy

The device potentially can “close the carbon cycle” in the development of syngas because it not only avoids emitting harmful gases, it also uses existing carbon dioxide in its process, Andrei said.

Moreover, even though the device uses sunlight, it also can work even under low levels of sunlight or on a rainy or overcast day, an unexpected bonus of the technology, researchers said. This means it can work not only in locations that generally get a lot of sun, but ones that don’t as well, they said.

The team published a paper on their work in the journal Nature Materials.

Researchers plan to continue their work in two key directions, Andrei told Design News. One is to scale the device up to roof-top prototypes. The other is to used the syngas it creates to develop sustainable liquid fuels, such as ethanol, which can replace fossil fuels in existing combustion engines, he said.

Elizabeth Montalbano is a freelance writer who has written about technology and culture for more than 20 years. She has lived and worked as a professional journalist in Phoenix, San Francisco and New York City. In her free time she enjoys surfing, traveling, music, yoga and cooking. She currently resides in a village on the southwest coast of Portugal.