Scientists continue to develop new multicomponent heterogeneous nanocatalysts that offer improved performance for industrially crucial processes such as CO oxidation. Mixed metal oxide nanoparticle catalysts have shown promise for mediating this type of air-cleanup chemistry, but researchers have had limited success in developing such catalysts. Now, an international team led by Nanfeng Zheng of Xiamen University in China has designed a wet-chemistry method for fabricating iron-nickel hydroxide-platinum nanoparticles by covering the surface of platinum nanocrystals with metal hydroxide monolayers. The researchers propose that Ni2+ plays a key role in preventing interface dehydration and that at the Fe3+-O-Pt interfaces, OH reacts with CO to form CO2. On the basis of this mechanism, the authors developed an alloy-assisted strategy to maximize the use of platinum. The result is a platinum nanocatalyst dotted with catalytic metal-hydroxide-platinum sites over 50% of the platinum (Science 2014, DOI: 10.1126/science.1252553). The particles are smaller than 5 nm in diameter. They find that these nanocatalysts remain capable of removing CO from humid air for one month.