We use surface analytical techniques for the in situ and in operando characterization of catalytic systems such as high temperature scanning tunneling microscopy (STM) and X-ray photoelectron spectroscopy (XPS). XPS allows the analysis of samples under environmental conditions when sealing them with ultra-thin, electron transparent graphene membranes. For this purpose, we study the catalytic synthesis of monolayer graphene (ML-g) with control at the atomic level.

a) Grown ML-g flake on Cu imaged in optical microscopy.

b) Low energy electron diffraction pattern taken from ML-g/Cu(111) evidencing the slight rotation of overlayer and substrate lattice.

c) Low energy electron microscopy of a small bilayer flake ontop of ML-g/Cu.

d) Atomically resolved STM image of ML-g on Ir(111). The slightly rotated g lattice (green arrows) induces a moiré pattern with a large supercell (white lines).