TY - GEN
T1 - Studies to the functioning of automotive exhaust catalysts using in-situ positron emission tomography
AU - Vonkeman, K.A.
AU - Jonkers, Gert
AU - Santen, van, R.A.
PY - 1991
Y1 - 1991
N2 - To elucidate reaction kinetics in exhaust catalysis, the application of a technique stemming from nuclear medicine, i.e., Positron Emission Tomog., was developed. Short lived positron emitting nuclides 11C (t1/2 = 20 min), 13N (t1/2 = 10 min) and 15O (t1/2 = 2 min) were used to synthesize actual reactant mols. such as 11CO, 11CO2, 11CH4, 13N2, 15OO, C15O, and C15OO. The labeled reactants could be monitored in a catalyst bed right through the reactor wall using a Positron Emission Tomograph, with a resoln. of 1 cm in place of 1 s in time. Thus, a large amt. of information on the residence time of the reactants is obtained directly from the catalyst surface under actual reaction conditions. The mechanism and the rate limiting step in the CO oxidn. on Pt under cold start conditions of a car was studied. A strong interaction was found between gas phase CO2 and CeO2 at the catalyst surface, whereby the O atoms contained in lattice CeO2 exchange rapidly with the O atoms of the adsorbed CO2
AB - To elucidate reaction kinetics in exhaust catalysis, the application of a technique stemming from nuclear medicine, i.e., Positron Emission Tomog., was developed. Short lived positron emitting nuclides 11C (t1/2 = 20 min), 13N (t1/2 = 10 min) and 15O (t1/2 = 2 min) were used to synthesize actual reactant mols. such as 11CO, 11CO2, 11CH4, 13N2, 15OO, C15O, and C15OO. The labeled reactants could be monitored in a catalyst bed right through the reactor wall using a Positron Emission Tomograph, with a resoln. of 1 cm in place of 1 s in time. Thus, a large amt. of information on the residence time of the reactants is obtained directly from the catalyst surface under actual reaction conditions. The mechanism and the rate limiting step in the CO oxidn. on Pt under cold start conditions of a car was studied. A strong interaction was found between gas phase CO2 and CeO2 at the catalyst surface, whereby the O atoms contained in lattice CeO2 exchange rapidly with the O atoms of the adsorbed CO2
U2 - 10.1016/S0167-2991(08)62982-1
DO - 10.1016/S0167-2991(08)62982-1
M3 - Conference contribution
SN - 0-444-88787-3
T3 - Studies in Surface Science and Catalysis
SP - 239
EP - 252
BT - CAPoC : international symposium on catalysis and automotive pollution control : proceedings, 2nd, Brussels, Belgium, September 10-13, 1990
A2 - Crucq, A.
PB - Elsevier
CY - Amsterdam
T2 - conference; CAPOC ; 2 (Brüssel/Belgien) : 1990.09.10-13; 1990-09-10; 1990-09-13
Y2 - 10 September 1990 through 13 September 1990
ER -