A review; in general, reaction mechanisms in heterogeneous catalysis are difficult to reveal, because of the complexity of the reaction system. Our approach employs mass-selected metal clusters as well-defined model reaction centers. Chem. reactions on these clusters are investigated in a temp. controlled radio frequency (rf)-ion trap setup. Product ion concns. as a function of storage time enable the detn. of reaction kinetics and reaction mechanisms of free clusters. As an example, the CO combustion reaction on small gold clusters is studied. It is known that supported gold clusters with few atoms up to nm size exhibit relevant catalytic properties. Our ion trap measurements reveal catalytic activity already for neg. charged gold dimers. When the reaction kinetics are investigated as a function of temp., an intermediate product with CO and O2 coadsorbed can be isolated. In contrast, small at. silver clusters have not been found relevant for catalytic oxidn. processes so far. Our investigations show for the first time evidence for a strongly size dependent catalytic activity of Agn-. [on SciFinder(R)]     «

A review; in general, reaction mechanisms in heterogeneous catalysis are difficult to reveal, because of the complexity of the reaction system. Our approach employs mass-selected metal clusters as well-defined model reaction centers. Chem. reactions on these clusters are investigated in a temp. controlled radio frequency (rf)-ion trap setup. Product ion concns. as a function of storage time enable the detn. of reaction kinetics and reaction mechanisms of free clusters. As an example, the CO com...     »

Catalysis Catalysts Combustion catalysts Combustion kinetics Reaction kinetics Reaction mechanism (catalysis with small free noble metal clusters) Noble metals Role: CAT (Catalyst use), CPS (Chemical process), PEP (Physical, engineering or chemical process), PRP (Properties), PROC (Process), USES (Uses) (catalysis with small free noble metal clusters) Adsorption (coadsorption catalysis with small free noble metal clusters) Clusters (metal catalysis with small free noble metal clusters) review catalysis small free noble metal cluster     «

Catalysis Catalysts Combustion catalysts Combustion kinetics Reaction kinetics Reaction mechanism (catalysis with small free noble metal clusters) Noble metals Role: CAT (Catalyst use), CPS (Chemical process), PEP (Physical, engineering or chemical process), PRP (Properties), PROC (Process), USES (Uses) (catalysis with small free noble metal clusters) Adsorption (coadsorption catalysis with small free noble metal clusters) Clusters (metal catalysis with small free noble metal clusters) review ca...     »