2021/06/11 by Se‐Ho Kim, Kim, Se-Ho, Su‐Hyun Yoo +23 · 1 citation
Earth and Planetary Sciences · Engineering · Materials Science · #Advanced Materials Characterization Techniques #Catalytic Processes in Materials Science #FOS: Physical sciences #Materials Science (cond-mat.mtrl-sci) #nanoparticles nucleation surface interactions
paper · pdf · doi:10.48550/arxiv.2106.06342
openalex publication_date 2021/06/11 · openalex created_date 2022/10/10 · openalex updated_date 2026/07/28
Metal nano-aerogels combine a large surface area, a high structural stability, and a high catalytic activity towards a variety of chemical reactions. The performance of such nanostructures is underpinned by the atomic-level distribution of their constituents. Yet monitoring their sub-nanoscale structure and composition to guide property optimization remains extremely challenging. Here, we synthesized Pd nano-aerogels from a K2PdCl4 precursor and two different NaBH4 reductant concentrations in distilled water. Atom probe tomography reveals that the aerogel is poly-crystalline and that impurities (Na, K) are integrated from the solution into grain boundaries. Ab initio calculations indicate that these impurities preferentially bound to the Pd-metal surface and are ultimately found in grain boundaries forming as the particles coalesce during synthesis, with Na atoms thermodynamically equilibrating with the surrounding solution and K atoms remaining between growing grains. If controlled, impurity integration, i.e. grain boundary decoration, may offer opportunities for designing new nano-aerogels.