Harnessing Renewable Energy to Convert CO2 into Clean Fuel

Scientists from Ohio State University have developed a method to convert captured carbon dioxide (CO₂) directly into methane using a unique nickel-based catalyst, significantly reducing energy requirements. The research was recently published in the Journal of the American Chemical Society.

This new approach for capturing and converting CO₂ into methane raises the possibility that future gas emissions could be turned into an alternative fuel using power generated from renewable sources.

Power plants, industries, and various forms of transportation produce CO₂, a greenhouse gas that contributes to global warming. Traditional carbon capture systems aim to isolate CO₂ from other gases and convert it into useful products. However, the large amount of energy required for these systems makes applying them on an industrial scale challenging.

The team successfully converted carbamate, the trapped form of CO₂, into methane by using nickel atoms arranged on an electrified surface. They found that nickel atoms, a widely available and cost-effective catalyst, were highly effective in facilitating this conversion.

We are going from a molecule that has low energy and producing from it a fuel that has high energy. What makes this so interesting is that others capture, recover, and then convert carbon dioxide in steps, while we save energy by doing these steps simultaneously.

Tomaz Neves-Garcia, Department of Chemistry and Biochemistry, The Ohio State University

Most importantly, streamlining the carbon capture process helps reshape scientists' understanding of the carbon cycle and is a crucial step toward developing more advanced strategies for faster and more efficient climate mitigation technologies.

We need to focus on spending the lowest energy possible for carbon capture and conversion. So instead of performing all the capture and conversion steps independently, we can combine it in a single step, bypassing wasteful energy processes.

Tomaz Neves-Garcia, Department of Chemistry and Biochemistry, The Ohio State University

According to Neves-Garcia, the field holds promise, even though many carbon capture techniques are still in their early stages and are being refined by researchers from various disciplines.

The carbon cycle could be closed by using renewable electricity to convert CO₂ into fuel. For example, burning methane releases CO₂, which could then be absorbed and converted back into methane, creating a continuous cycle of energy generation without contributing to global warming.

This work also marks the first time scientists have successfully converted carbamate to methane using electrochemistry. Previously, most researchers had only been able to produce carbon monoxide, despite several attempts to transform captured CO₂ into valuable products.

“Methane can be a really interesting product, but the most important thing is that this opens a path to develop more processes to convert captured CO₂  into other products,” he said.

To encourage the development of a range of sustainable carbon capture pathways, the team plans to continue investigating more chemical clean energy options in the future.

Everything always goes back to energy, and there is a lot of excitement and effort invested in the future of this field to save more of it.

Tomaz Neves-Garcia, Department of Chemistry and Biochemistry, The Ohio State University

Additional authors include Quansong Zhu and L. Robert Baker from Ohio State, Liane M. Rossi from the University of Sao Paulo, Mahmudul Hasan and Robert E. Warburton from Case Western Reserve University, Jing Li and Hailiang Wang from Yale University, as well as Zhan Jiang and Yongye Liang from the Southern University of Science and Technology.

Journal Reference:

Garcia, -N, T., et al. (2024) Integrated Carbon Dioxide Capture by Amines and Conversion to Methane on Single-Atom Nickel Catalysts. Journal of the American Chemical Society. doi.org/10.1021/jacs.4c09744.