Reactions of methyl groups on a non-reducible metal oxide: The reaction of iodomethane on stoichiometric α-Cr2O3(0001)

Dong, Yujung; Brooks, John D.; Chen, Tsung-Liang; Mullins, David R.; Cox, David F.

doi:10.1016/j.susc.2015.06.003

Title: Reactions of methyl groups on a non-reducible metal oxide: The reaction of iodomethane on stoichiometric α-Cr₂O₃(0001)

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Abstract

The reaction of iodomethane on the nearly stoichiometric α-Cr₂O₃₍0001) surface produces gas phase ethylene, methane, and surface iodine adatoms. The reaction is first initiated by the dissociation of iodomethane into surface methyl fragments, -CH₃, and iodine adatoms. Methyl fragments bound at surface Cr cation sites undergo a rate-limiting dehydrogenation reaction to methylene, =CH₂. The methylene intermediates formed from methyl dehydrogenation can then undergo coupling reactions to produce ethylene via two principle reaction pathways: (1) direct coupling of methylene and (2) methylene insertion into the methyl surface bond to form surface ethyl groups which undergo β-H elimination to produce ethylene. The liberated hydrogen also combines with methyl groups to form methane. Iodine adatoms from the dissociation of iodomethane deactivate the surface by simple site blocking of the surface Cr³⁺ cations.

Authors:

Dong, Yujung ^[1]; Brooks, John D. ^[1]; Chen, Tsung-Liang ^[2]; Mullins, David R. ^[2]; Cox, David F. ^[1]

Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States)
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

Publication Date:: Wed Jun 10 00:00:00 EDT 2015

Research Org.:: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

Sponsoring Org.:: USDOE Office of Science (SC), Basic Energy Sciences (BES)

OSTI Identifier:: 1212370

Alternate Identifier(s):: OSTI ID: 1244746

Grant/Contract Number:: AC05-00OR22725; FG02-97ER14751

Resource Type:: Accepted Manuscript

Journal Name:: Surface Science

Additional Journal Information:: Journal Volume: 641; Journal ID: ISSN 0039-6028

Publisher:: Elsevier

Country of Publication:: United States

Language:: English

Subject:: 37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; Cr2O3; methyl iodide; XPS; TPD; dehydrogenation

Citation Formats


                    Dong, Yujung, Brooks, John D., Chen, Tsung-Liang, Mullins, David R., and Cox, David F. Reactions of methyl groups on a non-reducible metal oxide: The reaction of iodomethane on stoichiometric α-Cr2O3(0001).  United States: N. p., 2015. 
Web.  doi:10.1016/j.susc.2015.06.003.

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                    Dong, Yujung, Brooks, John D., Chen, Tsung-Liang, Mullins, David R., & Cox, David F. Reactions of methyl groups on a non-reducible metal oxide: The reaction of iodomethane on stoichiometric α-Cr2O3(0001).  United States.  https://doi.org/10.1016/j.susc.2015.06.003

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                    Dong, Yujung, Brooks, John D., Chen, Tsung-Liang, Mullins, David R., and Cox, David F. Wed .  
"Reactions of methyl groups on a non-reducible metal oxide: The reaction of iodomethane on stoichiometric α-Cr2O3(0001)".  United States.  https://doi.org/10.1016/j.susc.2015.06.003.  https://www.osti.gov/servlets/purl/1212370.

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@article{osti_1212370,

  title        = {Reactions of methyl groups on a non-reducible metal oxide: The reaction of iodomethane on stoichiometric α-Cr2O3(0001)},

  author       = {Dong, Yujung and Brooks, John D. and Chen, Tsung-Liang and Mullins, David R. and Cox, David F.},

  abstractNote = {The reaction of iodomethane on the nearly stoichiometric α-Cr2O3(0001) surface produces gas phase ethylene, methane, and surface iodine adatoms. The reaction is first initiated by the dissociation of iodomethane into surface methyl fragments, -CH3, and iodine adatoms. Methyl fragments bound at surface Cr cation sites undergo a rate-limiting dehydrogenation reaction to methylene, =CH2. The methylene intermediates formed from methyl dehydrogenation can then undergo coupling reactions to produce ethylene via two principle reaction pathways: (1) direct coupling of methylene and (2) methylene insertion into the methyl surface bond to form surface ethyl groups which undergo β-H elimination to produce ethylene. The liberated hydrogen also combines with methyl groups to form methane. Iodine adatoms from the dissociation of iodomethane deactivate the surface by simple site blocking of the surface Cr3+ cations.},

  doi          = {10.1016/j.susc.2015.06.003},

  journal      = {Surface Science},

  number       = ,

  volume       = 641,

  place        = {United States},

  year         = {Wed Jun 10 00:00:00 EDT 2015},

  month        = {Wed Jun 10 00:00:00 EDT 2015}

}

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Title: Reactions of methyl groups on a non-reducible metal oxide: The reaction of iodomethane on stoichiometric α-Cr2O3(0001)

Abstract

Citation Formats

Title: Reactions of methyl groups on a non-reducible metal oxide: The reaction of iodomethane on stoichiometric α-Cr₂O₃(0001)