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takyon [soylentnews.org] writes:

Mars' underground brine could be a good source of oxygen [arstechnica.com]

MOXIE—the Mars Oxygen In-Situ Resource Utilization Experiment—is a box not much bigger than a toaster that produces oxygen from atmospheric CO₂. While a much larger version would be required to make liquid-oxygen fuel for a rocket, MOXIE is sized to produce about the amount of oxygen an active person needs to breathe.

A new study led by Pralay Gayen at Washington University in St. Louis, Missouri, tests a device that could tap a different resource—perchlorate brine believed to exist in the Martian ground at some locations. The device can split the water in that brine, producing pure oxygen and hydrogen.

[...] To test whether we could tap this resource, the researchers built an electrolysis device that they ran in Mars-like conditions. It uses a standard platinum-carbon cathode and a special lead-ruthenium-oxygen anode the researchers developed previously. They mixed up a plausible concentration of magnesium perchlorate brine and filled the headspace in that container with pure CO₂ for a Mars-like atmosphere. The whole thing was kept at -36°C (-33°F). When powered up, brine flowed through the device, splitting into pure oxygen gas captured on the anode side and pure hydrogen gas on the cathode side.

The device worked quite well, producing about 25 times as much oxygen as its MOXIE counterpart can manage. MOXIE requires about 300 watts of power to run, and this device matches that oxygen output on about 12 watts. Plus, it also produces hydrogen that could be used in a fuel cell to generate electricity. And it would be smaller and lighter than MOXIE, the researchers say. Ultimately, all this just illustrates that MOXIE is working with a lower quality—but more widely accessible—resource in atmospheric CO₂ instead of water.

Also at The Conversation [theconversation.com].

Fuel and oxygen harvesting from Martian regolithic brine [pnas.org] (DOI: 10.1073/pnas.2008613117) (DX [doi.org])

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