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Title: Acetylene and Ethylene Adsorption on a β-Mo 2C(100) Surface: A Periodic DFT Study on the Role of C- and Mo-Terminations for Bonding and Hydrogenation Reactions

Mo 2C catalysts are widely used in hydrogenation reactions; however, the role of the C and Mo terminations in these catalysts is not clear. Understanding the binding of adsorbates is key for explaining the activity of Mo 2C. The adsorption of acetylene and ethylene, probe molecules representing alkynes and olefins, respectively, was studied in this paper on a β-Mo 2C(100) surface with C and Mo terminations using calculations based on periodic density functional theory. Moreover, the role of the C/Mo molar ratio was investigated to compare the catalytic potential of cubic (δ-MoC) and orthorhombic (β-Mo 2C) surfaces. The geometry and electronic properties of the clean δ-MoC(001) and β-Mo 2C(100) surfaces have a strong influence on the binding of unsaturated hydrocarbons. The adsorption of ethylene is weaker than that of acetylene on the surfaces of the cubic and orthorhombic systems; adsorption of the hydrocarbons was stronger on β-Mo 2C(100) than on δ-MoC(001). The C termination in β-Mo 2C(100) actively participates in both acetylene and ethylene adsorption and is not merely a spectator. Finally, the results of this work suggest that the β-Mo 2C(100)-C surface could be the one responsible for the catalytic activity during the hydrogenation of unsaturated C≡C and C=Cmore » bonds, while the Mo-terminated surface could be poisoned or transformed by the strong adsorption of C and CH x fragments.« less
Authors:
 [1] ;  [2] ;  [1] ; ORCiD logo [3] ; ORCiD logo [3]
  1. Univ. of Antioquia, Medellin (Colombia)
  2. Univ. of Medellin (Colombia)
  3. Brookhaven National Lab. (BNL), Upton, NY (United States)
Publication Date:
Report Number(s):
BNL-114355-2017-JA
Journal ID: ISSN 1932-7447; R&D Project: CO040; KC0302010
Grant/Contract Number:
SC0012704
Type:
Accepted Manuscript
Journal Name:
Journal of Physical Chemistry. C
Additional Journal Information:
Journal Volume: 121; Journal Issue: 36; Journal ID: ISSN 1932-7447
Publisher:
American Chemical Society
Research Org:
Brookhaven National Lab. (BNL), Upton, NY (United States); Univ. of Antioquia, Medellin (Colombia)
Sponsoring Org:
USDOE Office of Science (SC); Colombian National Science Foundation (COLCIENCIAS) (Colombia); Univ. of Antioquia (Colombia)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
OSTI Identifier:
1395939

Jimenez-Orozco, Carlos, Florez, Elizabeth, Moreno, Andres, Liu, Ping, and Rodriguez, José A. Acetylene and Ethylene Adsorption on a β-Mo2C(100) Surface: A Periodic DFT Study on the Role of C- and Mo-Terminations for Bonding and Hydrogenation Reactions. United States: N. p., Web. doi:10.1021/acs.jpcc.7b05442.
Jimenez-Orozco, Carlos, Florez, Elizabeth, Moreno, Andres, Liu, Ping, & Rodriguez, José A. Acetylene and Ethylene Adsorption on a β-Mo2C(100) Surface: A Periodic DFT Study on the Role of C- and Mo-Terminations for Bonding and Hydrogenation Reactions. United States. doi:10.1021/acs.jpcc.7b05442.
Jimenez-Orozco, Carlos, Florez, Elizabeth, Moreno, Andres, Liu, Ping, and Rodriguez, José A. 2017. "Acetylene and Ethylene Adsorption on a β-Mo2C(100) Surface: A Periodic DFT Study on the Role of C- and Mo-Terminations for Bonding and Hydrogenation Reactions". United States. doi:10.1021/acs.jpcc.7b05442. https://www.osti.gov/servlets/purl/1395939.
@article{osti_1395939,
title = {Acetylene and Ethylene Adsorption on a β-Mo2C(100) Surface: A Periodic DFT Study on the Role of C- and Mo-Terminations for Bonding and Hydrogenation Reactions},
author = {Jimenez-Orozco, Carlos and Florez, Elizabeth and Moreno, Andres and Liu, Ping and Rodriguez, José A.},
abstractNote = {Mo2C catalysts are widely used in hydrogenation reactions; however, the role of the C and Mo terminations in these catalysts is not clear. Understanding the binding of adsorbates is key for explaining the activity of Mo2C. The adsorption of acetylene and ethylene, probe molecules representing alkynes and olefins, respectively, was studied in this paper on a β-Mo2C(100) surface with C and Mo terminations using calculations based on periodic density functional theory. Moreover, the role of the C/Mo molar ratio was investigated to compare the catalytic potential of cubic (δ-MoC) and orthorhombic (β-Mo2C) surfaces. The geometry and electronic properties of the clean δ-MoC(001) and β-Mo2C(100) surfaces have a strong influence on the binding of unsaturated hydrocarbons. The adsorption of ethylene is weaker than that of acetylene on the surfaces of the cubic and orthorhombic systems; adsorption of the hydrocarbons was stronger on β-Mo2C(100) than on δ-MoC(001). The C termination in β-Mo2C(100) actively participates in both acetylene and ethylene adsorption and is not merely a spectator. Finally, the results of this work suggest that the β-Mo2C(100)-C surface could be the one responsible for the catalytic activity during the hydrogenation of unsaturated C≡C and C=C bonds, while the Mo-terminated surface could be poisoned or transformed by the strong adsorption of C and CHx fragments.},
doi = {10.1021/acs.jpcc.7b05442},
journal = {Journal of Physical Chemistry. C},
number = 36,
volume = 121,
place = {United States},
year = {2017},
month = {8}
}