TY - JOUR
T1 - Fischer-Tropsch synthesis
T2 - Deuterium kinetic isotope study for hydrogenation of carbon oxides over cobalt and iron catalysts
AU - Gnanamani, Muthu Kumaran
AU - Jacobs, Gary
AU - Shafer, Wilson D.
AU - Sparks, Dennis
AU - Davis, Burtron H.
PY - 2011/10
Y1 - 2011/10
N2 - The hydrogenation of CO2 using Pt promoted Co/γ-Al 2O3 and doubly (Cu, K) promoted iron catalysts exhibits an inverse isotope effect (rH/rD < 1). The observed inverse isotope effect for hydrogenation of CO2 shows that hydrogen addition to CO2 should be involved in the kinetically relevant step. The systematic increase of inverse isotope effect with carbon number of products obtained during H2-D2-H2 switching experiments suggests the possible existence of a common intermediate (CH x O) for hydrogenation of CO2 over both cobalt and iron FT catalysts. The magnitude of the inverse isotope effect is lower for CO2 compared to CO hydrogenation under similar reaction conditions. The deuterium isotope effect does not provide a definite conclusion regarding the mechanism which CO 2 hydrogenation follows (alkyl, enol, or alkylidine mechanisms).
AB - The hydrogenation of CO2 using Pt promoted Co/γ-Al 2O3 and doubly (Cu, K) promoted iron catalysts exhibits an inverse isotope effect (rH/rD < 1). The observed inverse isotope effect for hydrogenation of CO2 shows that hydrogen addition to CO2 should be involved in the kinetically relevant step. The systematic increase of inverse isotope effect with carbon number of products obtained during H2-D2-H2 switching experiments suggests the possible existence of a common intermediate (CH x O) for hydrogenation of CO2 over both cobalt and iron FT catalysts. The magnitude of the inverse isotope effect is lower for CO2 compared to CO hydrogenation under similar reaction conditions. The deuterium isotope effect does not provide a definite conclusion regarding the mechanism which CO 2 hydrogenation follows (alkyl, enol, or alkylidine mechanisms).
KW - CO insertion mechanism
KW - Cobalt
KW - Enol mechanism
KW - High alpha Fe
KW - Hydrogenation of carbon oxides
KW - Inverse isotope effect
KW - Low alpha Fe: alkyl mechanism
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U2 - 10.1007/s10562-011-0673-4
DO - 10.1007/s10562-011-0673-4
M3 - Article
AN - SCOPUS:80053587367
SN - 1011-372X
VL - 141
SP - 1420
EP - 1428
JO - Catalysis Letters
JF - Catalysis Letters
IS - 10
ER -