MIT chemical engineers have pioneered a highly efficient process for converting carbon dioxide (CO2) into carbon monoxide (CO), a crucial chemical precursor that holds promise for generating valuable compounds like ethanol and various fuels.
This breakthrough method, if scaled up for industrial applications, could play a pivotal role in mitigating greenhouse gas emissions by capturing CO2 from power plants and other sources and repurposing it for profitable chemical production.
The innovative approach leverages electricity to drive the chemical conversion process, aided by a catalyst anchored to the electrode surface using strands of DNA. Acting like Velcro, these DNA strands ensure close proximity of all reaction components, significantly enhancing reaction efficiency compared to traditional methods where components are dispersed in solution.
Ariel Furst, the Paul M. Cook Career Development Assistant Professor of Chemical Engineering and senior author of the study, envisions the transformative potential of this technology for decarbonization efforts. Furst’s venture, Helix Carbon, aims to further refine and commercialize this groundbreaking approach.
Converting CO2 into useful products necessitates its initial conversion into CO, typically achieved through electrocatalysis. However, conventional electrochemical methods entail prohibitively high energy costs.
To address this challenge, researchers have explored the use of electrocatalysts, including porphyrins—a class of molecules akin to those found in blood’s oxygen-carrying heme. These catalysts accelerate the reaction while reducing energy input. However, conventional setups suffer from inefficiencies as CO2 and catalysts have limited encounters at the electrode surface.
To enhance reaction efficiency, Furst’s team devised a method to tether catalysts to the electrode using DNA, capitalizing on its sequence-specific Velcro-like properties. By attaching DNA strands to both the electrode and catalyst, they achieve a reversible bond, enabling catalysts to bind selectively to the electrode surface.
Applying an electrical potential to the electrode, the catalyst utilizes this energy to convert CO2 into CO, with water generating a small amount of hydrogen gas as a byproduct. Crucially, this approach achieves 100% Faradaic efficiency—directly converting electrical energy into chemical reactions without waste—compared to only 40% without DNA tethering.
The technology’s scalability for industrial deployment is facilitated by the affordability of carbon electrodes and catalysts devoid of precious metals. The researchers also aim to explore the synthesis of other products like methanol and ethanol using this approach, underscoring its versatility and potential impact on commercial applications. Through Helix Carbon, efforts are underway to advance this technology for widespread adoption in decarbonization initiatives and chemical manufacturing.
