Cornell University scientists re-purposed the 120-year-old Cottrell equation to understand how carbon dioxide reacts when subjected to electrochemistry, with the goal of turning the gas into useful materials. The researchers hope that the classic equation can help electrochemists control reactions to produce desirable products like ethylene, ethane or ethanol, turning an environmental problem into a renewable resource.
Scientists at Cornell University have revised the Cottrell equation, a century-old electrochemical equation, to help transform atmospheric carbon dioxide into a functional substance and help manage this greenhouse gas.
Named after chemist Frederick Gardner Cottrell, who discovered it in 1903, this equation now serves as a valuable tool for modern-day researchers. By using the electrochemical method in a controlled laboratory environment, scientists can gain a clearer understanding of the various reactions that carbon dioxide can undergo.
Electrochemical reduction of carbon dioxide offers the opportunity to transform the gas from an environmental liability into a feedstock for chemical products or, as in nature, as a storage medium for renewable electricity in the form of chemical bonds.
Their works were published in the journal ACS catalysis.
„For carbon dioxide, the better we understand the reaction pathways, the better we can control the reaction — which is what we want in the long term,” said lead author Riley Gasbold DiDomenico. Professor Tobias Hanrath.
„If we have better control over the reaction, we can do what we want when we want to do it,” DiDomenico said. „The Cottrell equation is the tool to get there.”
The equation enables a researcher to identify and control experimental parameters for taking carbon dioxide and converting it to useful carbon products such as ethylene, ethane, or ethanol.
Many researchers today use advanced computational methods to provide a detailed atomistic picture of processes at the catalyst surface, but these methods often involve many nuanced assumptions that complicate direct comparisons with experiments, said senior author Tobias Hanrath.
„The great thing about this old equation is that there are very few assumptions,” Hanrath said. „If you add experimental data, you get a better sense of the truth. It’s an old classic. That’s the part I thought was beautiful.
DiDomenico said: „Because it’s old, the Cottrell equation is a forgotten technique. It’s classic electrochemistry. It’s cool to bring it back to people’s minds. I think this equation will help other electrochemists study their own systems.
Reference: “Mechanistic Insights into the Formation of CO and C2 Products in Electrochemical CO2 Reduction─Role of Sequential Charge Transfer and Chemical Reactions” Rileigh Casebolt DiDomenico, Kelsey Levine, Laila Reimanis, Héctor and D. Abruñath, 2 March 27 . ACS catalysis.
DOI: 10.1021/acscatal.2c06043
The research was funded by the National Science Foundation, a Cornell Energy Systems Institute-Corning Graduate Fellowship, and the Cornell Engineering Learning Initiative.