Fuel cells turn chemicals into electricity. Now, a team from the University of Toronto’s Faculty of Applied Science & Engineering has adapted technology from fuel cells to do the reverse: harness electricity to make valuable chemicals from waste carbon dioxide.
The research was recently published in the journal Science.
“For decades, talented researchers have been developing systems that convert electricity into hydrogen and back again,” says University Professor Ted Sargent of the Edward S. Rogers Sr. department of electrical and computer engineering,who is one of the senior authors of the paper.
“Our innovation builds on that legacy, but, by using carbon-based molecules, we can plug directly into existing hydrocarbon infrastructure.”
In a hydrogen fuel cell, hydrogen and oxygen come together on the surface of a catalyst. The chemical reaction releases electrons, which are captured by specialized materials within the fuel cell and pumped into a circuit.
The opposite of a fuel cell is an electrolyzer, which uses electricity to drive a chemical reaction. The paper’s authors are experts in designing electrolyzers that convert CO2 into other carbon-based molecules, such as ethylene. The team includes PhD candidate Adnan Ozden, who is supervised by Professor David Sinton in the department of mechanical and industrial engineering, as well as several members of Sargent’s team, including PhD candidate Joshua Wicks, post-doctoral researcher F. Pelayo García de Arquer and former post-doctoral researcher Cao-Thang Dinh.
“Ethylene is one of the most widely produced chemicals in the world,” says Wicks. “It’s used to make everything from antifreeze to lawn furniture. Today it is derived from fossil fuels, but if we could instead make it by upgrading waste CO2, it would provide a new economic incentive for capturing carbon.”