Solution of the structure of the high-coverage CO layer on the Ru(0001) surface-A combined study by density functional theory and scanning tunneling microscopy.

Structures formed by dense CO adsorption layers can provide information about the balance between molecule-surface and molecule-molecule interactions. However, in many cases, the structure models are not clear. Using density functional theory (DFT) and scanning tunneling microscopy (STM), we have investigated the high-coverage CO layer on the Ru(0001) surface.

Growing polymers, caught in the act.

Researchers show the polymerization of ethylene at the active centers of a catalyst.

A highly sensitive gas chromatograph for in situ and operando experiments on catalytic reactions.

We describe an automated gas sampling and injection unit for a gas chromatograph (GC). It has specially been designed for low concentrations of products formed in catalytic in situ and operando experiments when slow reactions on single crystal models are investigated. The unit makes use of a buffer volume that is filled with gas samples from the reactor at a reduced pressure.

Method for the Manual Analysis of Moiré Structures in STM images.

A method is presented to manually determine the lattice parameters of commensurate hexagonal moiré structures resolved by STM. It solves the problem that lattice parameters of moiré structures usually cannot be determined by inspection of an STM image, so that computer-based analyses are required. The lattice vector of a commensurate moiré structure is a sum of integer multiples both of the two basis vectors of the substrate and of the adsorbed layer.

Density fluctuations as door-opener for diffusion on crowded surfaces.

How particles can move on a catalyst surface that, under the conditions of an industrial process, is highly covered by adsorbates and where most adsorption sites are occupied has remained an open question. We have studied the diffusion of O atoms on a fully CO-covered Ru(0001) surface by means of high-speed/variable-temperature scanning tunneling microscopy combined with density functional theory calculations. Atomically resolved trajectories show a surprisingly fast diffusion of the O atoms, almost as fast as on the clean surface.