TY - JOUR
T1 - Modeling the adsorbate coverage distribution over a multi-faceted catalytic grain in the presence of an electric field
T2 - O/Fe from first principles
AU - Bray, Jacob
AU - Hensley, Alyssa J.R.
AU - Collinge, Greg
AU - Che, Fanglin
AU - Wang, Yong
AU - McEwen, Jean Sabin
N1 - Publisher Copyright:
© 2018 Elsevier B.V.
PY - 2018/8/15
Y1 - 2018/8/15
N2 - The impact of an external electric field on the concerted behavior of oxygen over a multi-faceted catalytic Fe grain is determined via the interpolation of ab initio models of oxygen adsorption on Fe(100), Fe(110), and Fe(111) in the presence of an external electric field. The application of both negative and positive electric fields weaken the adsorption strength for oxygen on all three surface facets, with Fe(110) experiencing the greatest effect. Kinetic models of a multi-faceted catalytic Fe grain show that the average oxygen coverage over the grain surface is reduced under the influence of both a negative and positive electric field, which are consistent with phase diagram results at comparable pressures. Furthermore, we show that there is a weak synergistic effect between a Pd promoter and a positive electric field on the oxygen adsorption energy, i.e. the Pd promoter and electric field combination weaken the oxygen adsorption energy to a greater degree than the simple addition of both components separately. Overall, the work shows that the application of an applied external electric field may be a useful tool in fine-tuning chemical properties of Fe-based catalysts in hydrodeoxygenation applications.
AB - The impact of an external electric field on the concerted behavior of oxygen over a multi-faceted catalytic Fe grain is determined via the interpolation of ab initio models of oxygen adsorption on Fe(100), Fe(110), and Fe(111) in the presence of an external electric field. The application of both negative and positive electric fields weaken the adsorption strength for oxygen on all three surface facets, with Fe(110) experiencing the greatest effect. Kinetic models of a multi-faceted catalytic Fe grain show that the average oxygen coverage over the grain surface is reduced under the influence of both a negative and positive electric field, which are consistent with phase diagram results at comparable pressures. Furthermore, we show that there is a weak synergistic effect between a Pd promoter and a positive electric field on the oxygen adsorption energy, i.e. the Pd promoter and electric field combination weaken the oxygen adsorption energy to a greater degree than the simple addition of both components separately. Overall, the work shows that the application of an applied external electric field may be a useful tool in fine-tuning chemical properties of Fe-based catalysts in hydrodeoxygenation applications.
KW - Field ion microscopy
KW - Heterogeneous catalysis
KW - Hydrodeoxygenation
KW - Iron
KW - Mean field model
KW - Oxygen
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U2 - 10.1016/j.cattod.2018.04.016
DO - 10.1016/j.cattod.2018.04.016
M3 - Article
AN - SCOPUS:85047090651
SN - 0920-5861
VL - 312
SP - 92
EP - 104
JO - Catalysis Today
JF - Catalysis Today
ER -