The polymn. of acetylene was studied by thermal programmed reaction on model catalysts consisting of size-selected Ag, Rh, and Pd atoms and Pdn (1≤n≤30) clusters on well-characterized MgO(111) thin films. In a single-pass heating cycle expt., benzene, butadiene, and butane were catalyzed with different selectivities as function of cluster size: palladium and rhodium atoms selectively produce benzene, and the highest selectivity for butadiene is obsd. for Pd6, whereas Pd20 reveals the highest selectivity for butane. Ag atoms are inert. These results provide an atom-by-atom observation of the selectivity of small cluster catalysts. [on SciFinder(R)]     «

The polymn. of acetylene was studied by thermal programmed reaction on model catalysts consisting of size-selected Ag, Rh, and Pd atoms and Pdn (1≤n≤30) clusters on well-characterized MgO(111) thin films. In a single-pass heating cycle expt., benzene, butadiene, and butane were catalyzed with different selectivities as function of cluster size: palladium and rhodium atoms selectively produce benzene, and the highest selectivity for butadiene is obsd. for Pd6, whereas Pd20 reveals the highest...     »

CAN 148:121288 22-5 Physical Organic Chemistry Lehrstuhl fuer Physikalische Chemie, Technische Universitaet Muenchen, Garching, Germany. Journal 1063-777X 1309-48-4 (Magnesium oxide) Role: CAT (Catalyst use), USES (Uses) (catalyst support; cyclotrimerization and oligomerization of acetylene on supported metal clusters); 7440-05-3 (Palladium); 7440-16-6 (Rhodium); 7440-22-4 (Silver); 62863-33-6 (Palladium cluster (Pd13)); 66554-19-6 (Palladium cluster (Pd6)); 126928-76-5 (Palladium cluster (Pd4)); 150385-95-8 (Palladium cluster (Pd8)); 151247-60-8; 266317-62-8 Role: CAT (Catalyst use), USES (Uses) (cyclotrimerization and oligomerization of acetylene on supported metal clusters); 74-86-2 (Acetylene) Role: RCT (Reactant), RACT (Reactant or reagent) (cyclotrimerization and oligomerization of acetylene on supported metal clusters); 71-43-2P (Benzene); 106-97-8P (Butane); 106-99-0P (Butadiene) Role: SPN (Synthetic preparation), PREP (Preparation) (cyclotrimerization and oligomerization of acetylene on supported metal clusters)     «

CAN 148:121288 22-5 Physical Organic Chemistry Lehrstuhl fuer Physikalische Chemie, Technische Universitaet Muenchen, Garching, Germany. Journal 1063-777X 1309-48-4 (Magnesium oxide) Role: CAT (Catalyst use), USES (Uses) (catalyst support; cyclotrimerization and oligomerization of acetylene on supported metal clusters); 7440-05-3 (Palladium); 7440-16-6 (Rhodium); 7440-22-4 (Silver); 62863-33-6 (Palladium cluster (Pd13)); 66554-19-6 (Palladium cluster (Pd6)); 126928-76-5 (Palladium cluster...     »