Humans on Mars will need oxygen, and Mars’ atmosphere is pretty anemic when it comes to the life-sustaining element. NASA’s Perseverance rover successfully extracted oxygen from CO2 in Mars’ atmosphere, but there are other ways to acquire it. There seem to be vast amounts of water buried under the Martian surface, and oxygen in the water is just waiting to be set free from its bonds with hydrogen.
On Earth, that’s no problem. Just run an electrical current through water, and you get oxygen. But Mars won’t give up its oxygen so easily.
NASA’s Perseverance rover extracted oxygen from CO2 in Mars’ atmosphere, another first for the mission. It was an exciting achievement since future human visitors to Mars will need it to breathe and to create rocket fuel. But a team of Chinese scientists are developing a different approach.
They’ve shared their results in a paper titled “Automated synthesis of oxygen-producing catalysts from Martian meteorites by a robotic AI chemist.” It’s published in Nature Synthesis, and the lead authors are from the Key Laboratory of Precision and Intelligent Chemistry at the University of Science and Technology of China, Hefei, China.
“Oxygen supply must be the top priority for any human activity on Mars because rocket propellants and life support systems consume substantial amounts of oxygen, which cannot be replenished from the Martian atmosphere,” the authors write. (NASA scientists might disagree with that statement.)
Instead, Chinese researchers think that solar energy can be used to produce oxygen from Martian water. But it won’t be the simple electrolysis from science class. Instead, they intend to employ catalysts.
Simple electrolysis involves running an electric current through water to produce oxygen and hydrogen. Image Credit: By © Nevit Dilmen, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=10959462
Simple electrolysis faces barriers that limit its potential and productivity. The oxygen evolution reaction is a bottleneck in electrolysis, and scientists sometimes call electrolysis “sluggish.” On Earth, scientists know which catalysts can overcome the bottleneck. But conditions are different on Mars than they are on Earth. Scientists can’t just transpose methods that work on Earth onto Mars. The trick is finding the appropriate catalysts available on Mars. Scientists call them oxygen evolution reaction (OER) catalysts.
Here’s the problem: there are over three million possible catalysts on Mars. How can scientists work through all those possibilities when the communication delay between Mars and Earth can be up to 20 minutes long? It’s not practical.
This is another situation where robotics and AI can solve a problem, according to the research team.
“Here we demonstrate a robotic artificial-intelligence chemist for automated synthesis and intelligent optimization of catalysts for the oxygen evolution reaction from Martian meteorites,” the researchers explain. “The entire process, including Martian ore pretreatment, catalyst synthesis, characterization, testing and, most importantly, the search for the optimal catalyst formula, is performed without human intervention.”
China doesn’t have a functioning spacecraft on Mars that can do some of this work. Fortunately, nature has delivered samples of Mars to Earth in the form of meteorites. The researchers used small amounts of five types of Martian meteorites as feedstock in their automated system.