Pyridine adsorption and reaction on Mo(110) and C/N–Mo(110): experiment and modeling

Abdallah, Wael; Nelson, Alan E.; Gray, Murray R.

doi:10.1016/j.susc.2004.07.037

Cited by 10 publications

(7 citation statements)

References 53 publications

(64 reference statements)

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“…We note, in passing, that these authors make plausible estimates of the missing VdW contributions to the adsorption energies of 0.21 and 0.15 eV per molecule in the most stable geometries on Cu{110} and Ag{110}, respectively, based upon a semi-empirical correction scheme proposed by Grimme (2006). Abdallah et al (2004) report calculations for pyridine adsorption on Mo{110}, a flat bcc surface (Pratt et al 2005;Jenkins & Pratt 2007), in which the strongest binding is found for a flat-lying adsorbate geometry with the N atom and the two 'meta' C atoms located in near-atop sites (adsorption energy 1.54 eV per molecule). Upright models were found to bind far less strongly (with a maximum reported adsorption energy of just 0.66 eV per molecule), although the authors suggest that such a state may become populated at high coverage (Abdallah et al 2004).…”

Section: (A) Pyridine and Pyrrolementioning

confidence: 94%

“…Abdallah et al (2004) report calculations for pyridine adsorption on Mo{110}, a flat bcc surface (Pratt et al 2005;Jenkins & Pratt 2007), in which the strongest binding is found for a flat-lying adsorbate geometry with the N atom and the two 'meta' C atoms located in near-atop sites (adsorption energy 1.54 eV per molecule). Upright models were found to bind far less strongly (with a maximum reported adsorption energy of just 0.66 eV per molecule), although the authors suggest that such a state may become populated at high coverage (Abdallah et al 2004).…”

Section: (A) Pyridine and Pyrrolementioning

confidence: 99%

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Aromatic adsorption on metals via first-principles density functional theory

2009

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We review first-principles calculations relevant to the adsorption of aromatic molecules on metal surfaces. Benzene has been intensively studied on a variety of substrates, providing an opportunity to comment upon trends from one metal to another. Meanwhile, calculations elucidating the adsorption of polycyclic aromatic molecules are more sparse, but nevertheless yield important insights into the role of non-covalent interactions. Heterocyclic and substituted aromatic compounds introduce the complicating possibility of electronic and steric effects, whose relative importance can thus far only be gauged on a case-by-case basis. Finally, the coadsorption and/or reaction of aromatic molecules is discussed, highlighting an area where the predictive power of theory is likely to prove decisive in the future.

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Section: (A) Pyridine and Pyrrolementioning

confidence: 94%

Section: (A) Pyridine and Pyrrolementioning

confidence: 99%

Aromatic adsorption on metals via first-principles density functional theory

2009

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“…As the simplest model of nitrogen-containing heterocyclic compounds, pyridine (C 5 H 5 N) has been widely used as a probe molecule to study the HDN mechanism both experimentally 16 and theoretically. 17 It is accepted that pyridine hydrogenation on the MoP catalyst follows the classical Horiuti−Polanyi mechanism, 18 i.e., hydrogen atoms are added sequentially. In order to elucidate the hydrogenation pathways; in this article, we study the first two hydrogenation steps of pyridine on MoP(001), based on the self-consistent periodic density functional theory (DFT).…”

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Initial Hydrogenations of Pyridine on MoP(001): A Density Functional Study

Guo

Zhu

et al. 2012

Langmuir

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The initial hydrogenations of pyridine on MoP(001) with various hydrogen species are studied using self-consistent periodic density functional theory (DFT). The possible surface hydrogen species are examined by studying interaction of H(2) and H(2)S with the surface, and the results suggest that the rational hydrogen source for pyridine hydrogenations should be surface hydrogen atoms, followed by adsorbed H(2)S and SH. On MoP(001), pyridine has two types of adsorption modes, i.e., side-on and end-on; and the most stable η(5)(N,C(α),C(β),C(β),C(α)) configuration of the side-on mode facilitates the hydrogenation of pyridine. The optimal hydrogenation path of pyridine with surface hydrogen atoms in the Langmuir-Hinshelwood mechanism is the formation of 3-monohydropyridine, followed by producing 3,5-dihydropyridine, in which the two-step hydrogenations take place on the C(β) atoms. When adsorbed H(2)S is considered as the source of hydrogen, slightly higher hydrogenation barriers are always involved, while the energy barriers for hydrogenations involving adsorbed SH are much lower. However, the hydrogenation of pyridine should be suppressed by the adsorption of H(2)S, and the promotion effect of adsorbed SH is limited.

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“…Numerous experimental and theoretical studies have been reported investigating the adsorption and reaction of basic organonitrogen compounds, specifically pyridine and its derivatives, on model transition metal catalyst surfaces to understand the mechanistic features of hydrodenitrogenation (HDN) chemistry. − Although these studies have provided incremental gains in HDN catalyst activity, fundamental questions remain regarding nonbasic (pyrrole) organonitrogen adsorption on molybdenum-based hydrotreating catalyst surfaces. Pyrrole (C 4 H 5 N) is a nonbasic organonitrogen heterocycle in which the lone electron pair of nitrogen is delocalized over the π-system of the ring. , The lone-pair electrons of the nitrogen atom and the two CC bonds form a six-electron conjugated π-electron system.…”

Section: Introductionmentioning

confidence: 99%

Density Functional Theory Study of Pyrrole Adsorption on Mo(110)

Abdallah

Nelson

2005

J. Phys. Chem. B

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The objective of the present study is to identify possible adsorption configurations of pyrrole on Mo(110) using density functional theory (DFT) calculations. Several adsorption configurations were studied including pyrrole and pyrrolyl adsorption as parallel, perpendicular, and tilted adsorption modes relative to the Mo(110) surface plane. Based on the DFT calculations, pyrrole is suggested to adsorb in a parallel mode with respect to the Mo(110) surface through its pi-orbital as mu3,eta(5)-Pyr-0 degrees with an adsorption energy of -28.7 to -31.5 kcal mol(-1). The possibility of a coexisting mode where pyrrole adsorbs on the surface with a slightly tilted molecular plane as mu3,eta(4)(N,C2,C3,C4)-Pyr-5 degrees is also likely to occur, particularly at higher pyrrole coverages. The slightly tilted configuration is suggested to arise from the lateral interactions of adsorbed pyrrole on Mo(110), and not the result of a phase transformation on the surface since this requires a relatively high activation energy as indicated by additional linear synchronous transit (LST)/quadratic synchronous transit (QST) calculations. Both adsorption geometries bond to three surface Mo atoms, and Mo(110) did not promote hydrogen abstraction. Pyrrolyl adsorption on Mo(110) is energetically possible, but unlikely to occur because gas-phase hydrogen has not been previously experimentally observed as a pyrrole decomposition product on Mo(110).

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Pyridine adsorption and reaction on Mo(110) and C/N–Mo(110): experiment and modeling

Cited by 10 publications

References 53 publications

Aromatic adsorption on metals via first-principles density functional theory

Aromatic adsorption on metals via first-principles density functional theory

Initial Hydrogenations of Pyridine on MoP(001): A Density Functional Study

Density Functional Theory Study of Pyrrole Adsorption on Mo(110)

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