As mentioned before, buoyancy is lacking in space. This is an issue when we want gasses to rise up out of liquids. On Earth, the force of gravity is what causes buoyancy, allowing for matter of different densities to fall or rise when mixed together. However, the microgravity of space does not allow for this kind of buoyancy, making it harder to move the oxygen needed for astronauts out of the water.
This is the problem that using magnets would solve. As described in the paper exploring this method, researchers used magnetic properties on various types of liquid to draw out the gas bubbles. In order to replicate the conditions of microgravity, they carried out their experiments at the ZARM drop tower, where weightlessness will occur within airtight capsules dropped at about 394 feet.
These experiments show that a much more efficient method of producing air for astronauts can be achieved, and they could allow us to venture even further into space.