Yale scientists combine plasma and electricity to convert CO2 into sustainable aviation fuel

Scientists at Yale University have developed a system that combines plasma and electricity to convert carbon dioxide (CO2) into valuable chemicals, including methanol and butane. The research was led by Dr. Lea Winter, assistant professor of chemical and environmental engineering at Yale. Winter and her team sought to combine plasma with electrocatalysis. Plasma is often referred to as the fourth state of matter, after solid, liquid, and gas. It is a high-energy gas in which electrons have been stripped from atoms, forming charged particles. Winter noted that this approach can convert CO2 into fuels, pharmaceuticals, solvents, and other chemicals derived from fossil fuels.

She added: "The multi-carbon products we generate with this approach are very useful for many chemical industries." It can also produce precursor chemicals for sustainable aviation fuel.

Combining Plasma and Electrocatalysis

Breaking down CO2: Although CO2 is relatively abundant, it has not yet been widely used to produce valuable products. This is because it is a highly stable and inert molecule, and converting it into useful substances requires large amounts of energy. Electrocatalysis is a promising solution. It uses electricity and catalysts to drive chemical reactions that convert CO2 into other compounds. However, electrocatalysis alone typically produces only a relatively limited range of simple carbon products. The Yale team therefore considered combining electrocatalysis with plasma, which contains high-energy electrons. These electrons excite CO2 molecules and weaken their bonds before they reach the catalyst.

The catalyst can then use these activated species to form different products. Winter noted that plasma opens up chemical pathways that electrocatalysis cannot reach on its own.

An Innovative Solution: The Three-Phase Interface

However, these plasma-electrochemical processes typically rely on a water interface, which can limit their effectiveness. While plasma can activate CO2 gas, water may quench and neutralize the most reactive plasma species before they reach the catalyst. Winter added: "Identifying how to effectively combine plasma with the catalyst so that we can actually see the effects of plasma and allow these plasma-excited species to participate in catalytic reactions has been a challenge."

Overcoming the limitation: To address this problem, the scientists proposed a three-phase interface that brings gas, liquid, and solid components together. It simultaneously prevents the plasma from interacting directly with water. The system relies on a gas diffusion electrode, a membrane made from the same type of material used in non-stick pans. It is partially covered with a thin layer of copper that acts as the electrocatalyst. Its pores are large enough to allow plasma particles to pass through the catalyst layer, meet protons in the water, and drive chemical reactions. According to the scientists, the approach has achieved the highest yields to date in producing valuable alcohols and three- and four-carbon-atom compounds.

These products can be used for liquid fuels, pharmaceuticals, and other valuable products. The team will next optimize the catalysts and experiment with other materials.

Commercial Potential and Applications

The system also operates at room temperature and atmospheric pressure, which could make commercialization easier. Winter summarized in a press release: "This is a plug-and-play process. You can turn it on or off whenever electricity is available. It can also run directly on intermittent renewable electricity, so we could see retrofits of existing plants, meaning you don't need to build an entirely new plant around it." The research has been published in the journal Nature Catalysis.

Implications of This Technology for Sustainable Energy

The Yale research demonstrates the promise of combining plasma with electrocatalysis, offering a new method for converting carbon dioxide. As the global demand for reducing carbon emissions grows, this technology can effectively transform CO2 into sustainable aviation fuel and other chemicals, making it significant for environmental protection and energy transition. In addition, the system operates at room temperature and atmospheric pressure, lowering the technical barriers to commercialization and potentially enabling the retrofitting of existing plants to achieve more efficient energy use.