Scientists Turn CO₂ Into High-Performance Fuels Using Nickel Catalyst

Chemists from the National University of Singapore (NUS) have developed a nickel-based catalyst that converts CO₂ into high-performance liquid fuels, offering a cleaner route to sustainable aviation and automotive energy.

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The scientists' findings, published in Nature Catalysis, could help to cut emissions while providing sustainable fuel alternatives.

Research has long tried to address the challenge of transforming waste CO2 into energy-rich materials. Most studies have focused on copper catalysts, which can turn CO2 into usable materials such as ethylene or ethanol. However, these methods have consistently struggled to produce longer, branched hydrocarbon chains, which are essential for high-performance fuels. 

The NUS team, led by Associate Professor Boon Siang YEO, tested a Ni-based catalyst instead. They found that they could precisely steer the electrochemical reduction of carbon dioxide by injecting a small quantity of fluoride ions into the nickel structure and using pulsed potential electrolysis.

This gave them control over the sorts of hydrocarbons generated, whether straight chains or branched molecules. Branched hydrocarbons are particularly sought after as they burn more efficiently and perform better in engines, making them ideal for cars and planes.

Using pulsed potential electrolysis, in which the electrical bias is adjusted in periodic cycles, the team was able to significantly boost the branch-to-linear ratio of hydrocarbons containing five or more carbon atoms, outperforming conventional approaches by more than 400 %.

They found that fluoride doping the nickel catalyst helped to retain its oxidation state throughout the electrochemical reduction process, enabling the production of longer hydrocarbon chains. The team also showed that nickel helps remove oxygen from reaction intermediates and encourages asymmetric coupling between unsaturated hydrocarbon species and adsorbed carbon monoxide.

Copper, by contrast, tends to convert oxygen-containing intermediates into alcohols, limiting the formation of longer, more complex hydrocarbons. Nickel's behaviour enables the creation of products similar to those from high-temperature industrial processes like Fischer–Tropsch synthesis.

This work brings together complementary expertise in catalyst synthesis, mechanistic investigation and computational modelling, which allows us to uncover new mechanisms and design strategies for carbon dioxide reduction to long-chain hydrocarbons. This work would not have been possible, if not for the intense collaboration between experimentalists and theoreticians.

Boon Siang YEO, Associate Professor, Department of Chemistry, National University of Singapore

This study's significance extends beyond improving the fundamental understanding of carbon dioxide electroreduction processes.

A key advancement of our work is that we were able to reveal why copper-based catalysts, despite being heavily studied by the community over the past ten years, are not able to form appreciable amounts of long-chain hydrocarbons, as compared to nickel catalysts.

Boon Siang YEO, Associate Professor, Department of Chemistry, National University of Singapore

The findings open the door to producing on-demand, sustainable aviation fuels and chemical precursors by precisely controlling the structure of hydrocarbons made from CO₂ using electricity, an important step in the shift to greener technologies.

Journal Reference:

Ou, Y., et al. (2025) Controlling hydrocarbon chain growth and degree of branching in CO₂ electroreduction on fluorine-doped nickel catalysts. Nature Catalysis. doi.org/10.1038/s41929-025-01370-1.