To establish the structure-catalytic property relationships of heterogeneous catalysts, a detailed characterization of the three-dimensional (3D) distribution of active sites on a single catalyst is essential. Single-particle catalysis of a modular multilayer catalytic platform that consists of a solid silica core, a mesoporous silica shell, and uniformly distributed Pt nanoparticles sandwiched in between these layers is presented. The first 3D high-resolution super-localization imaging of single fluorescent molecules produced at active sites on the core-shell model nanocatalysts is demonstrated. The 3D mapping is aided by the well-defined geometry and a correlation study in scanning electron microscopy and total internal reflection fluorescence and scattering microscopy. This approach can be generalized to study other nano- and mesoscale structures.
Keywords: heterogeneous catalysis; mesoporous silica; multilayer nanocatalysts; platinum; three-dimensional imaging.
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