Spectroscopic identification and imaging of surface processes occurring at microscopic and mesoscopic scales

X-ray photoemission electron microscopy (XPEEM) and low energy electron microscopy (LEEM) were successfully combined with scanning photoelectron microscopy (SPEM) to probe in situ the propagation of reaction fronts and thoroughly characterize the induced complex surface morphology, involving changes in the local structure and chemical state of the substrate and the adsorbed layer. It was found that the oxidation fronts in water formation reaction on a Au-modified Ru(1 1 0) surface trigger redistribution of the initially uniform Au adlayer. It is accompanied by massive reconstruction and deconstruction of the substrate surface and development of a 'patterned' interface consisting of separated adsorption phases.