Carbon dioxide reactor makes Martian fuel

Tianyu Zhang, a University of Cincinnati student in chemical engineering holds up a vial of graphene that is used as a catalyst for converting carbon dioxide into methane. Credit: Andrew Higley/UC Creative
University of Cincinnati engineers are working on new ways to convert greenhouse gasses into fuel, which can be used to combat climate change and send astronauts to Mars.

Jingjie Wu, a professor at the UC College of Engineering and Applied Science, and his students used a catalyst to convert carbon dioxide into methane. It's also known as the "Sabatier Reaction" after Paul Sabatier, a French chemist who died in 2012. The International Space Station uses it to remove carbon dioxide from the air they breathe and to generate rocket fuel.

Wu thinks bigger.

Carbon dioxide is almost all that makes up the Martian atmosphere. Wu stated that astronauts could cut down on fuel by buying what they need on Mars once they reach it.

It's like a Mars gas station. Wu stated that you could pump carbon dioxide through the reactor and make methane for rockets.

The study by UC was published in Nature Communications, with collaborations from Rice University and Shanghai University.

Wu started his career in chemical engineering studying electric vehicle fuel cells. He then began to study carbon dioxide conversion in his chemical engineering laboratory around 10 years ago.

An experimental reactor that converts carbon dioxide into methane uses graphene quantum dots. Credit: Andrew Higley/UC Creative

Wu stated, "I realized that greenhouse gasses were going to be an important issue in society." "A lot countries have realized that carbon dioxide is an important issue for sustainable development. This is why I believe we must achieve carbon neutrality."

The Biden Administration set a goal to achieve a reduction of greenhouse gases pollutants by 50% by 2030, and an economy that is reliant on renewable energy by 2050.

Wu stated, "That means that we will have to recycle carbon dioxide."

Wu and his students, which include Tianyu Zhang (UC doctoral candidate), are experimenting using different catalysts, such as graphene quantum dolayersof carbon that are just nanometers in sizethat can increase methane yield.

Wu stated that the process has the potential to reduce climate change. It also offers a huge commercial advantage by producing fuel as a side product.

Professor Jingjie Wu (UC Chemical Engineering Assistant) and Tianyu Zhang (doctorate) are experimenting on different catalysts for converting carbon dioxide into storable fuel in order to combat climate change. Credit: Andrew Higley/UC Creative

"The process is now 100 times more productive than 10 years ago." Wu stated that you can see that progress will accelerate. "In the next ten years, there will be many startups to commercialize this technology."

Wu's students use different catalysts to make methane and ethylene. The world's most important chemical, Ethylene is used to make plastics, rubber and other products.

"Green energy will become very important. It will be a major market in the future. Zhang stated, "So I wanted to work with it."

Wu stated that the commercial viability of synthesising fuel from carbon dioxide is increased when it is combined with renewable energy like solar or wind power.

"We have too much green energy right now that we don't need and we throw it away." He said that we can store excess renewable energy in chemicals.

Jingjie Wu, a UC chemical engineer, is experimenting using different catalysts to convert carbon dioxide into fuels like methane in order to combat climate change. Credit: Andrew Higley/UC Creative

This process can be scaled up for power plants that can produce tons of carbon dioxide. It's also efficient because the conversion can occur right at the point where carbon dioxide is being produced.

Wu stated that advances in carbon dioxide fuel production make Wu more certain that humans will visit Mars within his lifetime.

He stated that to return to Mars from the present, you would need twice as much fuel. This is very heavy. You'll also need other fuels in the future. We can make methanol from carbon dioxide, and then use these to produce other downstream materials. Maybe one day, we will be able to live on Mars."

Learn more Making jet fuel from carbon dioxide

Tianyu Zhang and colleagues, Regulation of functional group on graphene quantum dot directs selective CO2-to-CH4 conversion, Nature Communications (2021). Information from Nature Communications: Tianyu Zhang and co, Regulation of functional group on graphene quantum dot directs selective CO2-to-CH4 conversion, (2021). DOI: 10.1038/s41467-021-25640-1