Cluster Size-Dependent Mechanisms of the CO + NO Reaction on Small Pdn (n ≤ 30) Clusters on Oxide Surfaces

The CO + NO reaction (2CO + 2NO → N2 + 2CO2) on small size-selected palladium clusters supported on thin MgO(100) films reveals distinct size effects in the size range Pdn with n ≤ 30. Clusters up to the tetramer are inert, while larger clusters form CO2 at around 300 K, and this main reaction mechanism involves adsorbed CO and an adsorbed oxygen atom, a reaction product from the dissocn. of NO. In addn., clusters consisting of 20-30 atoms reveal a low-temp. mechanism obsd. at temps. below 150 K; the corresponding reaction mechanism can be described as a direct reaction of CO with molecularly adsorbed NO. Interestingly, for all reactive cluster sizes, the reaction temp. of the main mechanism is at least 150 K lower than those for palladium single crystals and larger particles. This indicates that the energetics of the reaction on clusters are distinctly different from those on bulklike systems. In the presented one-cycle expts., the reaction is inhibited when strongly adsorbed NO blocks the CO adsorption sites. In addn., the obtained results reveal the interaction of NO with the clusters to show differences as a function of size; on larger clusters, both molecularly bonded and dissocd. NO coexist, while on small clusters, NO is efficiently dissocd., and hardly any molecularly bonded NO is detected. The desorption of N2 occurs on the reactive clusters between 300 and 500 K. [on SciFinder(R)]     «

The CO + NO reaction (2CO + 2NO → N2 + 2CO2) on small size-selected palladium clusters supported on thin MgO(100) films reveals distinct size effects in the size range Pdn with n ≤ 30. Clusters up to the tetramer are inert, while larger clusters form CO2 at around 300 K, and this main reaction mechanism involves adsorbed CO and an adsorbed oxygen atom, a reaction product from the dissocn. of NO. In addn., clusters consisting of 20-30 atoms reveal a low-temp. mechanism obsd. at temps. below 1...     »

Adsorbed substances Adsorption Catalysts Exhaust gases Flue gases Waste gases (cluster size-dependent mechanisms of CO + NO reaction on small Pdn (n ≤ 30) clusters on oxide surfaces) Oxides Role: CAT (Catalyst use), PRP (Properties), USES (Uses) (cluster size-dependent mechanisms of CO + NO reaction on small Pdn (n ≤ 30) clusters on oxide surfaces) Air pollution (control cluster size-dependent mechanisms of CO + NO reaction on small Pdn (n ≤ 30) clusters on oxide surfaces) Clusters (metal cluster size-dependent mechanisms of CO + NO reaction on small Pdn (n ≤ 30) clusters on oxide surfaces) Reaction mechanism (surface cluster size-dependent mechanisms of CO + NO reaction on small Pdn (n ≤ 30) clusters on oxide surfaces) palladium cluster size dependent mechanism nitrogen carbon oxide reaction     «

Adsorbed substances Adsorption Catalysts Exhaust gases Flue gases Waste gases (cluster size-dependent mechanisms of CO + NO reaction on small Pdn (n ≤ 30) clusters on oxide surfaces) Oxides Role: CAT (Catalyst use), PRP (Properties), USES (Uses) (cluster size-dependent mechanisms of CO + NO reaction on small Pdn (n ≤ 30) clusters on oxide surfaces) Air pollution (control cluster size-dependent mechanisms of CO + NO reaction on small Pdn (n ≤ 30) clusters on oxide surfaces) Clusters (metal...     »

CAN 139:11236 59-4 Air Pollution and Industrial Hygiene Institute of Surface Chemistry and Catalysis, University of Ulm, Ulm, Germany. Journal 0002-7863 1309-48-4 (Magnesia); 7440-05-3D (Palladium) Role: CAT (Catalyst use), PRP (Properties), USES (Uses) (cluster size-dependent mechanisms of CO + NO reaction on small Pdn (n ≤ 30) clusters on oxide surfaces); 630-08-0 (Carbon monoxide); 10102-43-9 (Nitric oxide) Role: CPS (Chemical process), PEP (Physical, engineering or chemical process), POL (Pollutant), PRP (Properties), RCT (Reactant), REM (Removal or disposal), OCCU (Occurrence), PROC (Process), RACT (Reactant or reagent) (cluster size-dependent mechanisms of CO + NO reaction on small Pdn (n ≤ 30) clusters on oxide surfaces)     «

CAN 139:11236 59-4 Air Pollution and Industrial Hygiene Institute of Surface Chemistry and Catalysis, University of Ulm, Ulm, Germany. Journal 0002-7863 1309-48-4 (Magnesia); 7440-05-3D (Palladium) Role: CAT (Catalyst use), PRP (Properties), USES (Uses) (cluster size-dependent mechanisms of CO + NO reaction on small Pdn (n ≤ 30) clusters on oxide surfaces); 630-08-0 (Carbon monoxide); 10102-43-9 (Nitric oxide) Role: CPS (Chemical process), PEP (Physical, engineering or chemical process), PO...     »