STRUCTURE OF CATALYTICALLY ACTIVE METALOXIDE SURFACES AND NANOSTRUCTURES USING SCANNING PROBE METHODS AND DENSITY FUNCTIONAL THEORY
WG1 members: Bjørk Hammer, Jeppe V. Lauritsen, Stefan Wendt
homepages:
Experiment (Lauritsen): inano.au.dk/organization/research-groups/nanocatalysis-lab-lauritsen/
SPM Group: phys.au.dk/forskning/forskningsomraader/condensed-matter-physics/spm/
Theory group (Hammer): www.phys.au.dk/~hammer
The activities of the iNANO members in the COST CM1104 action focuses on the atomic-scale description of surface structure of reducible oxides and the relation to catalytic or photocatalytic properties processes. The main experimental activities (Wendt, Lauritsen) are related to model catalysis studies of single crystal metal oxides (TiO2, ZnO, Al2O3 and MgAl2O4), nanoparticles supported on these oxides and metal oxide films or clusters grown on substrates (FeO, CoOx, MnOx).For this purpose we used a range of homebuilt variable-temperature Aarhus-type scanning probe microscopes (AFM and STM), which have been adapted to perform fast-scanning STM to record atom-resolved STM movies (link). Additional techniques in our lab are X-ray and UV Photoelectron Spectroscopy (with lab X-ray sources or at the Arhus Synchrotron ASTRID2) and temperature programmed desorption (TPD). The theory group works with automated structure optimization in conjunction with density functional theory methods. The structure of intrinsic point defects and topological defects, e.g. surface steps, are investigated and their chemical activity is probed. The theory group further works on metal cluster aggregation on reducible oxides.
The STM observation and DFT modeling of reduced oxide strands forming on highly reduced, stepped rutile TiO2(110) surfaces.
