Plasma direct exsolution at room temperature will enable improved sustainable synthetic routes, more control of catalysis microstructure as well as new application opportunities. Moreover, the factors that most affect the exsolution process are identified. It is shown that the surface defects produced initiate exsolution under a brief ion bombardment of an argon low-pressure and low temperature plasma. This results in controlled nanoparticles with diameters ≈19–22 nm with very high number densities thus creating a highly active catalytic material for CO oxidation which rivals traditionally created exsolved samples. (Advanced Energy Materials 12, 2022, 2201131).