Interrogative Kinetics A New Methodology for Catalyst Characterization. Theory Sergiy O. Shekhtman,...
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Interrogative Kinetics A New Methodology for Catalyst Characterization. Theory Sergiy O. Shekhtman, Gregory S. Yablonsky, John T. Gleaves. Dpt. of Chemical Engineering, Washington University, Campus Box 1198, One Brookings Drive, St. Louis, MO 63130, USA, fax: (314) 935-7211, e-mail: [email protected] CREL 2001
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Transcript of Interrogative Kinetics A New Methodology for Catalyst Characterization. Theory Sergiy O. Shekhtman,...
Interrogative Kinetics
A New Methodology for Catalyst Characterization.
Theory
Sergiy O. Shekhtman, Gregory S. Yablonsky,
John T. Gleaves.
Dpt. of Chemical Engineering, Washington University, Campus Box 1198, One Brookings Drive, St. Louis, MO 63130, USA,
fax: (314) 935-7211, e-mail: [email protected]
CREL 2001
The Theory of the Interrogative Kinetics Approach
State-Defining
Experiment
To explicitly separate diffusional transport and reaction. To identify the primary kinetic characteristics that can be independently measured in a TAP experiment. To relate the primary kinetic characteristics to detailed reaction mechanisms and distinguish them.
State-Altering
Experiment
To create and kinetically characterize different uniform catalyst states using TAP multi-pulse experiments. To extract the catalyst state characteristics from data obtained in a multi-pulse experiment (particularly the number of active sites). To make assumptions about the reaction mechanism
Interrogative Kinetics
A New Methodology for Catalyst Characterization.
Application to Furane Oxidation over VPO Catalyst
Sergiy O. Shekhtman, Gregory S. Yablonsky,
John T. Gleaves, Rebecca Fushimi
Dpt. of Chemical Engineering, Washington University, Campus Box 1198, One Brookings Drive, St. Louis, MO 63130, USA,
fax: (314) 935-7211, e-mail: [email protected]
CREL 2001
Multi-Pulse TAP ExperimentFurane Oxidation over VPO Catalyst
Furane Conversion.
-0.2
0.0
0.2
0.4
0.6
0.8
1.0
0 2000 4000 6000 8000 10000 12000Pulse Number
Con
versi
on
Furane Conversion intoMA
CO2
COAcrolein
Furane/Argon mixture (9/1) was pulsed over oxidized VPO catalyst at 400˚C
Multi-Pulse TAP ExperimentFurane Oxidation over VPO Catalyst
Furane Basic Kinetic Coefficients over Oxidized and “Relaxed” Catalyst
0
2000
4000
6000
8000
10000
0 0.2 0.4 0.6 0.8 1
Catalyst Reduction Degree
Ba
sic K
ineti
c C
oeff
icie
nt
r0,
r1
an
d r 2
Total amount of Furane moleculses converted by oxydized and "relaxed" catalysts are:
1 g of oxydized VPO = 1.4 1018
1 g of "relaxed" VPO = 0.64 1018
r0
r1
r2
Furane/Argon mixture (9/1) was pulsed over oxidized VPO catalyst at 400˚C. After catalyst had been completely reduced, it was left under vacuum conditions for 14
hrs. The, furane was pulsed again.
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