Direct Imaging of ALD Deposited Pt Nanoclusters inside the Giant Pores of MIL‐101

MIL‐101 giant‐pore metal‐organic framework (MOF) materials have been loaded with Pt nanoparticles using atomic layer deposition. The final structure has been investigated by aberration‐corrected annular dark‐field scanning transmission electron microscopy under strictly controlled low‐dose conditions. By combining the acquired experimental data with image simulations, the position of the small clusters within the individual pores of a metal‐organic framework has been determined. The embedding of the Pt nanoparticles is confirmed by electron tomography, which shows a distinct ordering of the highly uniform Pt nanoparticles. The results show that atomic layer deposition is particularly well‐suited for the deposition of individual nanoparticles inside MOF framework pores and that, upon proper regulation of the incident electron dose, annular dark‐field scanning transmission electron microscopy is a powerful tool for the characterization of this type of materials at a local scale.