Model systems in heterogeneous catalysis: Selectivity studies at the atomic level

Reaching 100% selectivity is the theme of the twentyfirst century in heterogeneous and heterogenized homogeneous catalysis. To study chemical reactivity at the atomic scale, model systems have been prepared and characterized. We discuss selectivity of hydrogenation and dehydrogenation reactions on supported Pd particles, methanol oxidation at vanadium oxide model catalysts and, at last, the design of model catalysts with a well defined charge state of the metal, i.e., An catalyst model systems.