Rather than using detectors to alert us to dangerous levels of indoor carbon monoxide, direct elimination of CO from enclosed spaces may offer a more cost-efficient approach.

Researchers from the U.S. and China developed titanium dioxide-supported tetraferroplatinum-iron oxide nanowires (NWs) that remove CO with a 100% conversion efficiency at room temperature.

Arrows represent a schematic illustration of the multiple reaction regimes for CO oxidation with the PtFe-FeOx/TiO2 system. Credit: Huiyuan Zhu et alA simple process for creating 1D nanostructures begins by assembling PtFe NWs onto the TiO₂ support. The NWs are then heated in air to cause Fe to diffuse to the surface, resulting in the PtFe-FeOx core-shell structure. The design maximizes the interfacial synergy of the system and improves catalytic performance.

Three unique mechanisms for CO conversion were revealed by isotope mass spectrometry. Two involve the interface between the PtFe and FeOx phases, and the remaining mechanism involves the interface between the NWs and the TiO₂. All three reactions combine to give the NWs the efficient 100% conversion of CO. The presence of Fe and FeOx on Pt also helps to prevent poisoning of the catalyst (deactivation through occupied binding sites).

Upon application of slight heating (40 °C), NWs that had begun to decrease in activity due to poisoning were rejuvenated and resumed catalytic function at 100 percent conversion. The NWs remained stable and active through this process for many cycles, demonstrating their durability.

This research can ideally be developed into a method for CO abatement, although the design of these unique NWs will also serve as inspiration for the design of advanced catalysts used in many different applications.

Collaborators from Oak Ridge National Laboratory, University of Tennessee, Zhejiang University of Technology, and Brookhaven National Laboratory participated in this research.