Forgotten Equation Could Be Key In Recycling CO2

By Brian Westenhaus - Apr 13, 2023

• Cornell scientists are using an electrochemical equation from 1903 to convert atmospheric CO2 into useful products.
• 
  
• The Cottrell equation is able to help researchers understand the CO2 reaction pathways, turning the gas from an environmental liability to a potential feedstock.
• 
  
• Recycling CO2 offers the opportunity to reduce the need to use fossil fuels, but cost and electricity supply, as well as political forces, are considerable challenges.

Cornell University scientists have dusted off an archaic – now 120 year old – electrochemical equation. The goal is to manage atmospheric carbon dioxide and convert the gas into a useful products.

The team’s work has been published in the journal ACS Catalysis.

The calculation – named the Cottrell equation for chemist Frederick Gardner Cottrell, who developed it in 1903 – can help today’s researchers understand the several reactions that carbon dioxide can take when electrochemistry is applied and pulsed on a lab bench.

The electrochemical reduction of carbon dioxide presents an opportunity to transform the gas from an environmental liability to a feedstock for chemical products or as a medium to store renewable electricity in the form of chemical bonds, as nature does.

Lead author Rileigh Casebolt DiDomenico, a chemical engineering doctoral student at Cornell under the supervision of Prof. Tobias Hanrath offered the background, “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. If we have better control over the reaction, then we can make what we want, when we want to make it. The Cottrell equation is the tool that helps us to get there.”

The equation enables a researcher to identify and control experimental parameters to take carbon dioxide and convert it into useful carbon products like ethylene, ethane or ethanol.

Professor Hanrath commented that many researchers today use advanced computational methods to provide a detailed atomistic picture of processes at the catalyst surface, but these methods often involve several nuanced assumptions, which complicate direct comparison to experiments.

“The magnificence of this old equation is that there are very few assumptions,” Hanrath said. “If you put in experimental data, you get a better sense of truth. It’s an old classic. That’s the part that I thought was beautiful.”

DiDomenico said, “Because it is older, the Cottrell equation has been a forgotten technique. It’s classic electrochemistry. Just bringing it back to the forefront of people’s minds has been cool. And I think this equation will help other electrochemists to study their own systems.”

The research was supported by the National Science Foundation, a Cornell Energy Systems Institute-Corning Graduate Fellowship and the Cornell Engineering Learning Initiative.

***

The idea to recycle CO2 is an attractive one. But the idea to “manage” the CO2 in the atmosphere is a bit alarming. That’s an idea where one finds the “Experts” that are going to decide on behalf of everyone. Its the questions of who, what, why and when, where, and how. Now the “experts” are telling us disaster is just few years away, after 50 years of about the same and being dead wrong. Trusting them with the fuel of life on earth is, well, alarming.

On the other hand! The atmosphere is nearing halfway to a CO2 content some think to be optimal. So the opportunity to recycle CO2 is becoming possible without dire threat. Recycling CO2 would put humanity into a current planetary carbon cycle. It could reduce the need to use fossil fuels exclusively. More resources is a good thing.

There is a catch. It takes electricity to reform the CO2. We’re not told how that might figure into the cost of the new products. The idea might die a death of a shortage of electrical power as the onslaught of the electric vehicle push is yet to really get into its stride. Last summer some people (California) didn’t have enough power to go around.

Its not science to blame, or industry or consumers. But the political forcing is going to be a severe problem, and soon.

By Brian Westenhaus via New Energy and Fuel