Research Highlights 2011

Catalyst Characterization

Aberration-corrected scanning transmission electron microscopy (STEM) combines sub-Angstrom resolution with outstanding analytical capabilities and thus provide an excellent tool for the characterization of heterogeneous catalysts. Images can be recorded with bright field (BF), annular dark field (ADF) and secondary electron (SE) detectors using various signals. The image shows Pd particles distributed on a (Si,Al)O_x support. All particles are visible in the ZC image but only those at the upper surface appear in the SE image. The comparison of these images provides information about the 3D structure.

Characterization of Catalysts in an Aberration-Corrected Scanning Transmission Electron Microscope
F. Krumeich, E. Müller, R. A. Wepf, and R. Nesper, J. Phys. Chem C 115 (2011) 1080–1083 DOI

Surface Properties and Morphology of Supported, Colloid-Derived Gold/Palladium Mono- and Bimetallic Nanoparticles
S. Marx, F. Krumeich, and A. Baiker
J. Phys. Chem. C 115 (2011) 8195-8205 DOI

Characterization of AuPd Nanoparticles by Probe-Corrected Scanning Transmission Electron Microscopy and X-Ray Absorption Spectroscopy
F. Krumeich, S. Marx, A. Baiker, and R. Nesper
Z. anorg. allg. Chem. 637 (2011) 875–881 DOI

Coated Nanoparticles

Composite nanoparticles and coated nanoparticles can be synthesized by flame spray pyrolysis of corresponding precorsor solutions (for detailed information, see PTL). The image shows silica coated Ag particles. In this case, the coating modifies the antibacterial activity of Ag.

Non-toxic Dry-coated Nanosilver for Plasmonic Biosensors
G. Sotiriou, T. Sannomiya, A. Teleki, F. Krumeich, J. Vörös, and S. E. Pratsinis
Adv. Funct. Mater. 20 (2010) 4250–4257 DOI

Nanosilver on Nanostructured Silica: Antibacterial Activity and Ag Surface Area
G. Sotiriou, A. Teleki, A. Camenzind, F. Krumeich, A. Meyer, S. Panke, and S. E. Pratsinis
Chem. Eng. J. 170 (2011) 547–554 DOI

Optimization of Catalysts

RuO₂ nanocrystals grown on SnO₂ microcrystal provide superior catalytic efficiency for the oxidation of HCl. In addition to the results published in this paper, EDXS analyses with high lateral resolution proved the expected elemental distribution (link).

Shaped RuO₂/SnO₂-Al₂O₃ Catalyst for Large-Scale Stable Cl₂ Production via HCl Oxidation
C. Mondelli, L. D. Pachón, A. Amrute, T. Schmidt, F. Krumeich, and J. Pérez-Ramírez
ChemCatChem 3 (2011) 657-660 DOI

Recent Research Hightlights