RT journal article T1 Quantitative 3D Characterization of Functionally Relevant Parameters in Heavy-Oxide-Supported 4d Metal Nanocatalysts A1 Marqueses Rodríguez, José A1 Manzorro Ureba, Ramón A1 Grzonka, Justyna María A1 Jiménez Benítez, Antonio Jesús A1 Cervera Gontard, Lionel A1 Hungría Hernández, Ana Belén A1 Calvino Gámez, José Juan A1 López Haro, Miguel A2 Ciencia de los Materiales e Ingeniería Metalúrgica y Química Inorgánica A2 Física de la Materia Condensada K1 Nanometrology K1 Nanometer-sized particles K1 Nano-catalyst K1 Metal supported K1 Metal particle K1 Electron tomography K1 Atomic numbers K1 American Chemical Society K1 3D characterization AB Accurate 3D nanometrology of catalysts with small nanometer-sized particles of light 3d or 4d metals supported on high-atomic-number oxides is crucial for understanding their functionality. However, performing quantitative 3D electron tomography analysis on systems involving metals like Pd, Ru, or Rh supported on heavy oxides (e.g., CeO2) poses significant challenges. The low atomic number (Z) of the metal complicates discrimination, especially for very small nanoparticles (1-3 nm). Conventional reconstruction methods successful for catalysts with 5d metals (e.g., Au, Pt, or Ir) fail to detect 4d metal particles in electron tomography reconstructions, as their contrasts cannot be effectively separated from those of the underlying support crystallites. To address this complex 3D characterization challenge, we have developed a full deep learning (DL) pipeline that combines multiple neural networks, each one optimized for a specific image-processing task. In particular, single-image super-resolution (SR) techniques are used to intelligently denoise and enhance the quality of the tomographic tilt series. U-net generative adversarial network algorithms are employed for image restoration and correcting alignment-related artifacts in the tilt series. Finally, semantic segmentation, utilizing a U-net-based convolutional neural network, splits the 3D volumes into their components (metal and support). This approach enables the visualization of subnanometer-sized 4d metal particles and allows for the quantitative extraction of catalytically relevant structural information, such as particle size, sphericity, and truncation, from compressed sensing electron tomography volume reconstructions. We demonstrate the potential of this approach by characterizing nanoparticles of a metal widely used in catalysis, Pd (Z = 46), supported on CeO2, a very high density (7.22 g/cm3) oxide involving a quite high-atomic-number element, Ce (Z = 58). PB American Chemical Society SN 0897-4756 YR 2023 FD 2023-09-14 LK http://hdl.handle.net/10498/31416 UL http://hdl.handle.net/10498/31416 LA eng DS Repositorio Institucional de la Universidad de Cádiz RD 06-nov-2026