Astronauts may be able to manufacture rocket fuel on Mars using carbon dioxide from the planet's atmosphere, according to a recent study. The technique, known as electrochemical reduction, allows for the conversion of CO2 into methane that is pure enough for use as a liquid propellant.

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This process involves electrolysis, where an electrical current drives a chemical reaction. Scientists have found that this method can produce methane, which is vital for rockets such as SpaceX’s Starship, designed for potential missions to Mars.

Carter Racine, a Ph.D. student at Texas A&M University and part of the study team led by University of Mississippi's Ahmed Badreldin, explained that transporting all necessary resources from Earth to Mars would be costly and complex. Their research focuses on utilizing in-situ resources to create the needed fuels and chemicals for space exploration.

Electrochemical reduction occurs in an electrolyzer, where water is oxidized at the anode, and electrons are transferred to carbon dioxide at the cathode, leading to the production of reduced carbon compounds. The choice of catalyst materials at the anode affects the types of compounds generated; for instance, a gold catalyst yields carbon monoxide, while a copper catalyst can create complex compounds, including methane.

What distinguishes Badreldin's team's work is the development of a nanometer-scale copper catalyst doped with nitrogen, which efficiently produces nearly pure methane. Previous methods for obtaining methane on Earth often resulted in unwanted byproducts that would be cumbersome to manage on Mars.

While NASA aims to send astronauts to Mars in the late 2030s or early 2040s, the process could have implications beyond space exploration. Racine noted that producing methane from atmospheric carbon dioxide could reduce reliance on fossil fuels.

However, converting CO2 into methane raises concerns about greenhouse gas emissions. Badreldin emphasized the need to explore methods that can store carbon for longer periods rather than cycling it back into the atmosphere. Although the absolute best solution to climate change involves the cessation of fossil fuel use altogether, producing methane through electrochemical reduction could serve as a transitional approach.

The study detailing this research was published in April in the journal ACS Catalysis.