Hybrid metal nanoparticles can allow separate reaction steps to occur in close proximity at different metal sites and accelerate catalysis. Prof. Nanfeng Zheng’s group synthesized iron-nickel hydroxide–platinum (transition metal-OH-Pt) nanoparticles with diameters below 5 nanometers and showed that they are highly efficient for carbon monoxide (CO) oxidation catalysis at room temperature. They characterized the composition and structure of the transition metal–OH-Pt interface and showed that Ni²⁺ plays a key role in stabilizing the interface against dehydration. Density functional theory and isotope-labeling experiments revealed that the OH groups at the Fe³⁺-OH-Pt interfaces readily react with CO adsorbed nearby to directly yield carbon dioxide (CO₂) and simultaneously produce coordinatively unsaturated Fe sites for O₂ activation. The oxide-supported PtFeNi nanocatalyst rapidly and fully removed CO from humid air without decay in activity for 1 month.（Science, 2014, 344, 495）