Catalyst can convert CO2 to ethanol

Ethanol, a well-established biofuel additive for gasoline, is traditionally produced from biomass such as corn or sugar cane. New research however, claims to have developed a catalyst to produce the fuel directly from carbon dioxide.

Scientists from the US Department of Energy’s Lawrence Berkeley National Laboratory have developed a new electrocatalyst made up of copper nanoparticles that can directly convert carbon dioxide into multicarbon fuels and alcohols using ‘record-low’ inputs of energy.

They’ve found that the electrocatalyst creates the conditions needed to break down carbon dioxide to form ethylene, ethanol and propanol.

“We discovered a catalyst for carbon dioxide reduction operating at high current density with a record low overpotential that is about 300 millivolts less than typical electrocatalysts," Peidong Yang, leader of the research, said in a statement.

Overpotential refers to the amount of extra voltage needed to drive a chemical reaction in excess of the thermodynamic potential of the products of that reaction. Put simply, the lower the overpotential, the more efficient the catalyst.

According to a statement from DOE, the new research is a prominent example of how carbon dioxide reduction has become an increasingly active area in energy research over recent years.

“Instead of harnessing the sun's energy to convert carbon dioxide into plant food, artificial photosynthesis seeks to use the same starting ingredients to produce chemical precursors commonly used in synthetic products as well as fuels like ethanol,” the statement reads.

Kim has estimated that if the catalyst were incorporated into an electrolyser as part of a solar fuel system, a material only 10 cm² could produce about 1.3 grams of ethylene, 0.8 grams of ethanol and 0.2 grams of propanol a day.

“With continued improvements in individual components of a solar fuel systems, those numbers should keep improving over time,” he said.

The research has recently been published in the Proceedings of the National Academy of Sciences.