Chemical selforganization of composite catalysts during catalytic reactions

Recent progress in the study of selforganization phenomena in catalytic reactions on multi-component surfaces is reviewed. As chemically more complex systems a Rh(1 1 1) surface with ultra-thin vanadium oxide layers (θ_V < 0.5 MLE) and a bimetallic Rh(1 1 1)/Ni surface, both subjected to the H₂ + O₂ reaction, were chosen. Applying spatially resolving methods in situ, it is shown that under reaction conditions a reversible redistribution of the components of the catalyst occurs. The redistribution processes are essentially driven by the different chemical affinities of the components to reacting species.