Hydrodechlorination reactions of 2-chloro-1,1,1,2-tetrafluoroethane and chloroethane in H2 and D2 on Pd catalysts

N. Chen; R. M. Rioux; F. H. Ribeiro

doi:10.1016/j.apcata.2004.02.049

Hydrodechlorination reactions of 2-chloro-1,1,1,2-tetrafluoroethane and chloroethane in H₂ and D₂ on Pd catalysts

N. Chen, R. M. Rioux, F. H. Ribeiro

Research output: Contribution to journal › Article › peer-review

6 Scopus citations

Abstract

Deuterium isotope exchange was employed to investigate some of the reaction steps for the hydrodechlorination of CF₃CFHCl and CH ₃CH₂Cl on supported Pd catalysts. Hydrodechlorination rates for both compounds using D₂ or H₂ were identical. It is concluded that H or D species are not involved in the rate-determining step of the hydrodechlorination reaction. Experiments using a combined H₂ and D₂ feed for hydrodechlorination of CF₃CFHCl showed that CF₃CFH₂ was preferentially formed over CF ₃CFHD. This experimental observation can be explained by isotope effects and is consistent with gas phase H₂ in equilibrium with adsorbed H and a reaction step consisting of the combination of surface adsorbed CF₃CFH - species with adsorbed H. Deuterated product distributions of CF₃CFHCl and CH₃CH₂Cl hydrodechlorination experiments with D₂ were analyzed to explore the reaction steps beyond the kinetically relevant steps. The main product of CF₃CFHCl hydrodechlorination was CF₃CFHD, showing that the C-Cl bond is preferentially broken. In the case of CH₃CH₂Cl, substantial C-H bond breaking accompanies the initial C-Cl scission. Deuterium exchange experiments with ethane on Pd/C and Pd/ZrO₂ were also investigated and the results indicate that the CH₃CH₂Cl product distribution is not caused by re-adsorption and subsequent exchange reaction of ethane.

Original language	English (US)
Pages (from-to)	85-94
Number of pages	10
Journal	Applied Catalysis A: General
Volume	271
Issue number	1-2
DOIs	https://doi.org/10.1016/j.apcata.2004.02.049
State	Published - Sep 10 2004

All Science Journal Classification (ASJC) codes

Catalysis
Process Chemistry and Technology

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10.1016/j.apcata.2004.02.049

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@article{9251948756f9476c8981959d01a2a9bd,

title = "Hydrodechlorination reactions of 2-chloro-1,1,1,2-tetrafluoroethane and chloroethane in H2 and D2 on Pd catalysts",

abstract = "Deuterium isotope exchange was employed to investigate some of the reaction steps for the hydrodechlorination of CF3CFHCl and CH 3CH2Cl on supported Pd catalysts. Hydrodechlorination rates for both compounds using D2 or H2 were identical. It is concluded that H or D species are not involved in the rate-determining step of the hydrodechlorination reaction. Experiments using a combined H2 and D2 feed for hydrodechlorination of CF3CFHCl showed that CF3CFH2 was preferentially formed over CF 3CFHD. This experimental observation can be explained by isotope effects and is consistent with gas phase H2 in equilibrium with adsorbed H and a reaction step consisting of the combination of surface adsorbed CF3CFH - species with adsorbed H. Deuterated product distributions of CF3CFHCl and CH3CH2Cl hydrodechlorination experiments with D2 were analyzed to explore the reaction steps beyond the kinetically relevant steps. The main product of CF3CFHCl hydrodechlorination was CF3CFHD, showing that the C-Cl bond is preferentially broken. In the case of CH3CH2Cl, substantial C-H bond breaking accompanies the initial C-Cl scission. Deuterium exchange experiments with ethane on Pd/C and Pd/ZrO2 were also investigated and the results indicate that the CH3CH2Cl product distribution is not caused by re-adsorption and subsequent exchange reaction of ethane.",

author = "N. Chen and Rioux, {R. M.} and Ribeiro, {F. H.}",

note = "Funding Information: We gratefully thank the National Science Foundation for funding through grant CTS-9702699. We thank Degussa for the 5% Pd/C catalyst. ",

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T1 - Hydrodechlorination reactions of 2-chloro-1,1,1,2-tetrafluoroethane and chloroethane in H2 and D2 on Pd catalysts

AU - Chen, N.

AU - Rioux, R. M.

AU - Ribeiro, F. H.

N1 - Funding Information: We gratefully thank the National Science Foundation for funding through grant CTS-9702699. We thank Degussa for the 5% Pd/C catalyst.

PY - 2004/9/10

Y1 - 2004/9/10

N2 - Deuterium isotope exchange was employed to investigate some of the reaction steps for the hydrodechlorination of CF3CFHCl and CH 3CH2Cl on supported Pd catalysts. Hydrodechlorination rates for both compounds using D2 or H2 were identical. It is concluded that H or D species are not involved in the rate-determining step of the hydrodechlorination reaction. Experiments using a combined H2 and D2 feed for hydrodechlorination of CF3CFHCl showed that CF3CFH2 was preferentially formed over CF 3CFHD. This experimental observation can be explained by isotope effects and is consistent with gas phase H2 in equilibrium with adsorbed H and a reaction step consisting of the combination of surface adsorbed CF3CFH - species with adsorbed H. Deuterated product distributions of CF3CFHCl and CH3CH2Cl hydrodechlorination experiments with D2 were analyzed to explore the reaction steps beyond the kinetically relevant steps. The main product of CF3CFHCl hydrodechlorination was CF3CFHD, showing that the C-Cl bond is preferentially broken. In the case of CH3CH2Cl, substantial C-H bond breaking accompanies the initial C-Cl scission. Deuterium exchange experiments with ethane on Pd/C and Pd/ZrO2 were also investigated and the results indicate that the CH3CH2Cl product distribution is not caused by re-adsorption and subsequent exchange reaction of ethane.

AB - Deuterium isotope exchange was employed to investigate some of the reaction steps for the hydrodechlorination of CF3CFHCl and CH 3CH2Cl on supported Pd catalysts. Hydrodechlorination rates for both compounds using D2 or H2 were identical. It is concluded that H or D species are not involved in the rate-determining step of the hydrodechlorination reaction. Experiments using a combined H2 and D2 feed for hydrodechlorination of CF3CFHCl showed that CF3CFH2 was preferentially formed over CF 3CFHD. This experimental observation can be explained by isotope effects and is consistent with gas phase H2 in equilibrium with adsorbed H and a reaction step consisting of the combination of surface adsorbed CF3CFH - species with adsorbed H. Deuterated product distributions of CF3CFHCl and CH3CH2Cl hydrodechlorination experiments with D2 were analyzed to explore the reaction steps beyond the kinetically relevant steps. The main product of CF3CFHCl hydrodechlorination was CF3CFHD, showing that the C-Cl bond is preferentially broken. In the case of CH3CH2Cl, substantial C-H bond breaking accompanies the initial C-Cl scission. Deuterium exchange experiments with ethane on Pd/C and Pd/ZrO2 were also investigated and the results indicate that the CH3CH2Cl product distribution is not caused by re-adsorption and subsequent exchange reaction of ethane.

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Hydrodechlorination reactions of 2-chloro-1,1,1,2-tetrafluoroethane and chloroethane in H₂ and D₂ on Pd catalysts

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