Jan 12 2021
For several years, scientists have taken efforts to convert the surplus atmospheric carbon dioxide into new fuels, chemicals, and other products conventionally made from hydrocarbons harnessed from fossil fuels.
Illinois researchers Andrew Gewirth, left, and Stephanie Chen designed a new copper-polymer electrode that can help recycle excess CO2 into ethylene, a useful carbon-based chemical that can be used as fuel. Image Credit: L. Brian Stauffer.
The recent drive to tackle the climatic impacts of greenhouse gases in the air has urged chemists to discover the most efficient way possible. A new study has come up with an electrochemical reaction, improved by polymers, to enhance the conversion efficiency of CO2 to ethylene compared to previous efforts.
Led by chemistry professor Andrew Gewirth and graduate student Xinyi (Stephanie) Chen from the University of Illinois Urbana-Champaign, the study findings have been published in the Natural Catalysis journal.
According to the study, making CO2 gas flow via a reaction chamber equipped with copper electrodes and an electrolyte solution is the usual technique to convert CO2 into useful carbon-containing chemicals.
Copper metal is highly selective toward the type of carbon that forms ethylene. Different electrode materials will produce different chemicals like carbon monoxide instead of ethylene, or a mix of other carbon chemicals. What we have done in this study is to design a new kind of copper electrode that produces almost entirely ethylene.
Andrew Gewirth, Chemistry Professor, University of Illinois Urbana-Champaign
The study reports that early studies have made use of other metals and molecular coatings on the electrode to help guide the CO2-reduction reactions. But these coatings are not firm and break down frequently during the reaction process and descend from the electrodes.
What we did differently in this study was to combine the copper ions and polymers into a solution, then apply that solution to an electrode, entraining the polymer into the copper.
Xinyi (Stephanie) Chen, Graduate Student, University of Illinois Urbana-Champaign
In the laboratory, the researchers discovered that the new polymer-entrained electrodes were not much prone to collapse and generated more stable chemical intermediates, leading to more effective ethylene production.
Chen stated, “We were able to convert CO2 to ethylene at a rate of up to 87%, depending on the electrolyte used. That is up from previous reports of conversion rates of about 80% using other types of electrodes.”
With the development of economic sources of electricity, combined with the increased interest in CO2-reduction technology, we see great potential for commercialization of this process.
Andrew Gewirth, Chemistry Professor, University of Illinois Urbana-Champaign
The study was financially supported by the International Institute for Carbon Neutral Energy Research, Shell’s New Energy Research and Technology, and the National Science Foundation.
Journal Reference:
Chen, X., et al. (2020) Electrochemical CO2-to-ethylene conversion on polyamine-incorporated Cu electrodes. Nature Catalysis. doi.org/10.1038/s41929-020-00547-0.