Unique Cluster-Support Effect of a Co₃O₄/TiO₂-3DHS Nanoreactor for Efficient Plasma-Catalytic Oxidation Performance

For environmental catalysis, a central topic is the design of high-performance catalysts and advanced mechanism studies. In the case of the removal of flue gas pollutants from coal-fired power plants, highly selective nanoreactors have been widely utilized together with plasma discharge characteristics, such as the catalytic oxidation of NO. Herein, a novel reactor with a three-dimensional hollow structure of TiO₂ confining Co₃O₄ nanoclusters (Co₃O₄/TiO₂-3DHS) has been developed for plasma-catalytic oxidation of NO, whose performance was compared with that of the commercial TiO₂ confining Co₃O₄ cluster (Co₃O₄/TiO₂). Specifically, Co₃O₄/TiO₂-3DHS presented a higher efficiency (almost 100%) within lower peak-peak voltage (V_P-P). More importantly, the NO oxidation efficiency was between 91.5 and 94.5% after a long time of testing, indicating that Co₃O₄/TiO₂-3DHS exhibits more robust sulfur and water tolerance. Density functional theory calculations revealed that such impressive performance originates from the unique cluster-support effect, which changes the distribution of the active sites on the catalyst surface, resulting in the selective adsorption of flue gas. This investigation provides a new strategy for constructing a three-dimensional hollow nanoreactor for the plasma-catalytic process.