Chemical Engineering team advances to close the carbon cycle

Friday, January 20, 2023
Zhongwei Chen with his research group

Professor Zhongwei Chen (bottom right) and some members of his research group

Professor Zhongwei Chen and his research team continue to advance toward closing the carbon cycle. In October, Chen’s research team published an article in the journal Nature Energy describing novel technology that could have a critical impact on the fight against climate change.

The system features devices known as electrolyzers that function within a reactor that converts CO2 into useful and environmentally benign chemicals such as ethanol using water and electricity. Primarily connected to climate change, CO2 is a  greenhouse gas produced by burning fossil fuels.

The research group, over the last seven years, has developed electrolyzers that have new electrodes and a new kind of liquid-based electrolyte, which is saturated with CO2 and flows through the devices for conversion into ethanol, methane, and other useful chemicals via an electrochemical reaction.

The electrolyzer could be directly fed CO2 emissions onsite, reducing costs by eliminating the need to capture and collect CO2 first.

Researchers have continued to optimize the design of the reactor to improve efficiency and affordability so that it can be a practical solution for industries that generate high CO2 emissions.

A new research paper has been published this month in the journal ACS Catalysis, chronicling the team’s advancement toward improving the design of the catalyst within the reactor. Professor Aiping Yu, University Research Chair, is also a contributing author.

“Right now, we can’t meet industrial requirements,” says Chen, a professor in the Department of Chemical Engineering. “So, we are designing catalysts with better activity, selectivity, and durability.”

Catalysts are commonly made from expensive metals such as palladium, copper, or tin. The lack of efficient catalysts is one of the reasons that electrochemical CO2 reduction technology has not been achieved on an industrial scale.

To overcome this challenge, Chen’s research team has developed a new catalyst made from carbon which fosters more active sites in each particle. Researchers designed a carbon interface with different active sides so the catalyst can be more efficient and durable.

diagram of chemical chains and of the hybrid carbon interface

An integral aspect of the development of the catalyst was done at Canadian Light Source, a national research facility, using a synchrotron light source. This equipment utilizes infrared, ultraviolet and x-ray light allowing researchers to observe the microscopic nature of matter right down to the level of the atom.

Using this characterization methodology Chen was able to examine the phase change and reaction within the catalyst, as well as how it degrades.

“The goal was to develop an efficient, durable catalyst for CO2 reduction in industry,” says Chen, Canada Research Chair in Advanced Materials for Clean Energy.” The development of this new catalyst allows for a cost-effective approach to carbon neutrality.”

Optimizing the catalyst is part of the journey to effectively expand the lab-scale version of the reactor to an industrial scale. This scale-up, as well as making the technology economically accessible to industry is a crucial step in closing the carbon cycle.