%0 Journal Article %1 Campbell1980 %A Campbell, C. T. %A Ertl, G. %A Kuipers, H. %A Segner, J. %D 1980 %I AIP %J J. Chem. Phys. %K BEAMS; CARBON CATALYSIS; COLLISIONS COLLISIONS; MOLECULAR MOLECULE MONOXIDE; OXIDATION; PLATINUM; SURFACES; %N 11 %P 5862-5873 %R 10.1063/1.440029 %T A molecular beam study of the catalytic oxidation of CO on a Pt(111) surface %U http://link.aip.org/link/?JCP/73/5862/1 %V 73 %X The oxidation of carbon monoxide catalyzed by Pt(111) was studied in ultrahigh vacuum using reactive molecular beam�surface scattering. Under all conditions studied, the reaction follows a Langmuir�Hinshelwood mechanism: the combination of a chemisorbed CO molecule and an oxygen adatom. When both reactants are at low coverage, the reaction proceeds with an activation energy E^*_LH =24.1 kcal/mole and a pre-exponential upsilon4 =0.11 cm2 particles-1 sec-1. At very high oxygen coverage, E^*_LH decreases to about 11.7 kcal/mole and upsilon4 to about 2�10-6 cm2 particles-1 sec-1. This is largely attributed to the corresponding increase in the energy of the adsorbed reactants. When a CO molecule incident from the gas phase strikes the surface presaturated with oxygen, it enters a weakly held precursor state to chemisorption. Desorption from this state causes a decrease in chemisorption probability with temperature. Once chemisorbed, the CO molecule then has almost unit probability of reacting to produce CO2 below 540 K. The CO2 product angular distribution varies from cosgamma to cos4gamma depending sensitively upon the adsorbed reactant concentrations.

@article{Campbell1980, abstract = {The oxidation of carbon monoxide catalyzed by Pt(111) was studied in ultrahigh vacuum using reactive molecular beam�surface scattering. Under all conditions studied, the reaction follows a Langmuir�Hinshelwood mechanism: the combination of a chemisorbed CO molecule and an oxygen adatom. When both reactants are at low coverage, the reaction proceeds with an activation energy E^*_LH =24.1 kcal/mole and a pre-exponential upsilon4 =0.11 cm2 particles-1 sec-1. At very high oxygen coverage, E^*_LH decreases to about 11.7 kcal/mole and upsilon4 to about 2�10-6 cm2 particles-1 sec-1. This is largely attributed to the corresponding increase in the energy of the adsorbed reactants. When a CO molecule incident from the gas phase strikes the surface presaturated with oxygen, it enters a weakly held precursor state to chemisorption. Desorption from this state causes a decrease in chemisorption probability with temperature. Once chemisorbed, the CO molecule then has almost unit probability of reacting to produce CO2 below 540 K. The CO2 product angular distribution varies from cosgamma to cos4gamma depending sensitively upon the adsorbed reactant concentrations.}, added-at = {2009-10-30T10:04:05.000+0100}, author = {Campbell, C. T. and Ertl, G. and Kuipers, H. and Segner, J.}, biburl = {https://www.bibsonomy.org/bibtex/257d55ef557e703341f18755b4503f7fc/jfischer}, doi = {10.1063/1.440029}, interhash = {14943be302b18abe13782496c95e62ff}, intrahash = {57d55ef557e703341f18755b4503f7fc}, journal = {J. Chem. Phys.}, keywords = {BEAMS; CARBON CATALYSIS; COLLISIONS COLLISIONS; MOLECULAR MOLECULE MONOXIDE; OXIDATION; PLATINUM; SURFACES;}, number = 11, pages = {5862-5873}, publisher = {AIP}, timestamp = {2009-10-30T10:04:10.000+0100}, title = {A molecular beam study of the catalytic oxidation of CO on a Pt(111) surface}, url = {http://link.aip.org/link/?JCP/73/5862/1}, volume = 73, year = 1980 }