Abstract
Density functional theory (DFT) calculations were used 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. 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.
| Original language | English |
|---|---|
| Pages (from-to) | 1595-1603 |
| Number of pages | 9 |
| Journal | Journal of Physical Chemistry C |
| Volume | 122 |
| Issue number | 3 |
| DOIs | |
| State | Published - Jan 25 2018 |
| Externally published | Yes |
Funding
This work was conducted as part of the Consortium for Computational Physics and Chemistry (CCPC), which is supported by the Bioenergy Technologies Office (BETO) of Energy Efficiency & Renewable Energy (EERE). We gratefully acknowledge the computing resources provided on “Blues”, a computing cluster operated by the Laboratory Computing Resource Center at Argonne National Laboratory (ANL). This research used resources of the National Energy Research Scientific Computing Center (NERSC), which is supported by the Office of Science of the U.S. Department of Energy under contract no. DE-AC02-05CH11231. Use of the Center for Nanoscale Materials was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under contract no. DE-AC02-06CH11357. The experimental part of this work has been coauthored by UT-Battelle, LLC under contract no. DE-AC05-00OR22725 with the U.S. Department of Energy. The United States Government and the publisher, by accepting the article for publication, acknowledge that the United States Government retains a nonexclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this manuscript, or allow others to do so, for United States Government purposes. The Department of Energy will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan (http://energy.gov/downloads/doe-public-access-plan). The work at ORNL was supported by the U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, Bioenergy Technologies Office through the Chemical Catalysis for Bioenergy consortium. This work was conducted as part of the Consortium for Computational Physics and Chemistry (CCPC), which is supported by the Bioenergy Technologies Office (BETO) of Energy Efficiency & Renewable Energy (EERE). We gratefully acknowledge the computing resources provided on Blues, a computing cluster operated by the Laboratory Computing Resource Center at Argonne National Laboratory (ANL). This research used resources of the National Energy Research Scientific Computing Center (NERSC), which is supported by the Office of Science of the U.S. Department of Energy under contract no. DE-AC02-05CH11231. Use of the Center for Nanoscale Materials was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under contract no. DE-AC02-06CH11357. The experimental part of this work has been coauthored by UT-Battelle, LLC under contract no. DE-AC05-00OR22725 with the U.S. Department of Energy. The work at ORNL was supported by the U.S. Department of Energy Office of Energy Efficiency and Renewable Energy, Bioenergy Technologies Office through the Chemical Catalysis for Bioenergy consortium.