skip to main content
DOE PAGES title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Ni-Doping Effects on Oxygen Removal from an Orthorhombic Mo2C (001) Surface: A Density Functional Theory Study

Abstract

Density functional theory (DFT) calculations were used in this paper to investigate the effect of Ni dopants on the removal of chemisorbed oxygen (O*) from the Mo-terminated (TMo) and C-terminated (TC) Mo2C(001) surfaces. The removal of adsorbed oxygen from the catalytic site is essential to maintain the long-term activity and selectivity of the carbide catalysts in the deoxygenation process related to bio-oil stabilization and upgrading. In this contribution, the computed reaction energetics and reaction barriers of O* removal were compared among undoped and Ni-doped Mo2C(001) surfaces. The DFT calculations indicate that selected Ni-doped surfaces such as Ni adsorbed on TMo and TC Mo2C(001) surfaces enable weaker binding of important reactive intermediates (O*, OH*) compared to the undoped counterparts, which is beneficial for the O* removal from the catalyst surface. This study thus confirms the promoting effect of the Ni dopant on O* removal reaction on the TMo Mo2C(001) and TC Mo2C(001) surfaces. Finally, this computational prediction has been confirmed by the temperature-programmed reduction profiles of Mo2C and Ni-doped Mo2C catalysts, which had been passivated and stored in an oxygen environment.

Authors:
 [1];  [2];  [3];  [1];  [2];  [2]
  1. Kansas State Univ., Manhattan, KS (United States). Dept. of Chemical Engineering
  2. Argonne National Lab. (ANL), Argonne, IL (United States). Materials Science Division
  3. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Publication Date:
Research Org.:
Argonne National Lab. (ANL), Argonne, IL (United States); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org.:
USDOE Office of Energy Efficiency and Renewable Energy (EERE), Bioenergy Technologies Office (EE-3B); USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
OSTI Identifier:
1423017
Alternate Identifier(s):
OSTI ID: 1425276
Grant/Contract Number:  
AC05-00OR22725; AC02-06CH11357; AC02-05CH11231
Resource Type:
Accepted Manuscript
Journal Name:
Journal of Physical Chemistry. C
Additional Journal Information:
Journal Volume: 122; Journal Issue: 3; Journal ID: ISSN 1932-7447
Publisher:
American Chemical Society
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY

Citation Formats

Zhou, Mingxia, Cheng, Lei, Choi, Jae-Soon, Liu, Bin, Curtiss, Larry A., and Assary, Rajeev S. Ni-Doping Effects on Oxygen Removal from an Orthorhombic Mo2C (001) Surface: A Density Functional Theory Study. United States: N. p., 2017. Web. doi:10.1021/acs.jpcc.7b09870.
Zhou, Mingxia, Cheng, Lei, Choi, Jae-Soon, Liu, Bin, Curtiss, Larry A., & Assary, Rajeev S. Ni-Doping Effects on Oxygen Removal from an Orthorhombic Mo2C (001) Surface: A Density Functional Theory Study. United States. doi:10.1021/acs.jpcc.7b09870.
Zhou, Mingxia, Cheng, Lei, Choi, Jae-Soon, Liu, Bin, Curtiss, Larry A., and Assary, Rajeev S. Fri . "Ni-Doping Effects on Oxygen Removal from an Orthorhombic Mo2C (001) Surface: A Density Functional Theory Study". United States. doi:10.1021/acs.jpcc.7b09870. https://www.osti.gov/servlets/purl/1423017.
@article{osti_1423017,
title = {Ni-Doping Effects on Oxygen Removal from an Orthorhombic Mo2C (001) Surface: A Density Functional Theory Study},
author = {Zhou, Mingxia and Cheng, Lei and Choi, Jae-Soon and Liu, Bin and Curtiss, Larry A. and Assary, Rajeev S.},
abstractNote = {Density functional theory (DFT) calculations were used in this paper to investigate the effect of Ni dopants on the removal of chemisorbed oxygen (O*) from the Mo-terminated (TMo) and C-terminated (TC) Mo2C(001) surfaces. The removal of adsorbed oxygen from the catalytic site is essential to maintain the long-term activity and selectivity of the carbide catalysts in the deoxygenation process related to bio-oil stabilization and upgrading. In this contribution, the computed reaction energetics and reaction barriers of O* removal were compared among undoped and Ni-doped Mo2C(001) surfaces. The DFT calculations indicate that selected Ni-doped surfaces such as Ni adsorbed on TMo and TC Mo2C(001) surfaces enable weaker binding of important reactive intermediates (O*, OH*) compared to the undoped counterparts, which is beneficial for the O* removal from the catalyst surface. This study thus confirms the promoting effect of the Ni dopant on O* removal reaction on the TMo Mo2C(001) and TC Mo2C(001) surfaces. Finally, this computational prediction has been confirmed by the temperature-programmed reduction profiles of Mo2C and Ni-doped Mo2C catalysts, which had been passivated and stored in an oxygen environment.},
doi = {10.1021/acs.jpcc.7b09870},
journal = {Journal of Physical Chemistry. C},
number = 3,
volume = 122,
place = {United States},
year = {2017},
month = {12}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record

Citation Metrics:
Cited by: 1 work
Citation information provided by
Web of Science

Figures / Tables:

Figure 1 Figure 1: Top view and side view of optimized structures of Mo2C(001) surfaces. (a) un-doped TMo Mo2C(001) surface, (b) un-doped TC Mo2C(001) surface. The top two layers of Mo atoms are depicted in different color to differentiate Mo on different positions. Same color scheme is utilized throughout the paper.

Save / Share:
Figures/Tables have been extracted from DOE-funded journal article accepted manuscripts.