Temperature-programmed reaction of methylamine on the Ni{100} surface

Chang, Che‐Chen; Khong, Cheng; Saiki, R.S.

doi:10.1116/1.578379

Cited by 23 publications

(10 citation statements)

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“…C−N bond activation has also been observed at ∼380 K for many organonitrogen compounds on nickel surfaces, often accompanied by the desorption of the products at reaction temperature. For methylamine on the Ni(100) surface, C−N bond cleavage is observed at 380 K, yielding NH 3 and CH 4 simultaneously. , NH 3 and C 6 H 6 are also observed at 380 K during aniline 2 and cyclohexylamine 28 hydrogenolysis on the Ni(111) surface. On the basis of this evidence we propose that for aniline adsorbed on the Ni(100) surface C−N bond activation occurs near 350 K with immediate desorption of the N-containing product at this temperature.…”

Section: Discussionmentioning

confidence: 98%

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Aniline Adsorption, Hydrogenation, and Hydrogenolysis on the Ni(100) Surface

1996

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The bonding and reactions of adsorbed aniline have been characterized on the Ni(100) surface both in hydrogen and in vacuum with a combination of surface spectroscopies. The structure of adsorbed aniline and derived intermediates has been characterized by near-edge X-ray absorption fine structure (NEXAFS) and X-ray photoemission spectroscopy (XPS). The dominant surface reactions have been studied using temperatureprogrammed reaction spectroscopy (TPRS) and in-situ temperature-programmed fluorescence yield nearedge spectroscopy (TP FYNES). Competition between hydrogenation, hydrogenolysis, and dehydrogenation of aniline in the 300-400 K temperature range depends markedly on hydrogen pressures in the vacuum to 0.01 Torr range. In the absence of external hydrogen, dehydrogenation dominates with increasing temperature. Both hydrogenation and hydrogenolysis of aniline-derived surface intermediates are enhanced dramatically by hydrogen atmospheres. For aniline coverages up to 1 monolayer, hydrogenolysis to form benzene at 475 K is dominant over a broad hydrogen pressure range (>10 -6 Torr). Ultrasoft X-ray absorption spectra above the carbon K edge of the aniline-derived surface intermediates reveal that the precursor for hydrogenolysis is a hydrogenated aniline-derived species indistinguishable from cyclohexylamine. In the presence of hydrogen, C-N bond activation appears to be correlated with unexpectedly large tilt angles near 55°observed at the hydrogenolysis temperature. In the absence of hydrogen atmospheres, low-temperature loss of amino hydrogen causes the ring to reorient even further away from the surface and therefore remain aromatic with increasing temperature. Both the resonant stabilization of the C-N bond and reorientation of the C-N bond away from the surface contribute to decreased C-N bond activation in the absence of external hydrogen.

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Section: Discussionmentioning

confidence: 98%

“…On the Ni(100) surface, the adsorption and reaction of methylamine, [5][6][7] pyridine, 8 and aniline 5 have been previously characterized using surface analytical methods. In an EELS study by Shirley et al, 6 CH 3 NH 2 was found to adsorb associatively through the nitrogen lone pair with the C-N bond basically parallel to the surface.…”

Section: Introductionmentioning

confidence: 99%

Aniline Adsorption, Hydrogenation, and Hydrogenolysis on the Ni(100) Surface

1996

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“…9 The selectivity of different catalysts in activating the C-H, N-H, and C-N bonds, as well as the mechanistic details, can be determined by studying methylamine decomposition. An abundance of experiments focused on the adsorption and decomposition of methylamine on Ni, 3,[9][10][11][12][13][14] Fe, 14 Cr, 3,13,14 Rh, 15 Pd, 16 Pt, [17][18][19] Mo, 20 W, 21 and Ru 22 surfaces have been performed with a variety of surface-sensitive techniques. The adsorption and decomposition of methylamine on Pt surfaces have been investigated with angle resolved ultraviolet photoemission spectroscopy (ARUPS), thermal desorption spectrometry (TDS), temperature programmed desorption (TPD), auger electron spectroscopy (AES), and electron energy loss spectroscopy (EELS).…”

Section: Introductionmentioning

confidence: 99%

Adsorption and decomposition of methylamine on a Pt(100) surface: a density functional theory study

Liu

Jin

et al. 2015

RSC Adv.

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“…1 Up to now, it is well-known that methylamine can be adsorbed through the nitrogen lone pair electrons on transition metal surfaces under UHV (ultrahigh vacuum) conditions, and the C-H, N-H or C-N bond can be activated at a high enough temperature. Several researchers have studied the adsorption and decomposition of methylamine on several metals, Ni, [2][3][4][5][6][7][8] Ru, 9 Pd, 10 Pt, 11,12 W, 13 Fe, 8 Cr, [6][7][8] Mo 14 and Rh. 15 The metallic Mo is very active, and it can be passivated by the carbon, nitrogen or oxygen overlayer.…”

Section: Introductionmentioning

confidence: 99%

Decomposition of methylamine on nitrogen atom modified Mo(100): a density functional theory study

Liu

Guo

et al. 2012

Phys. Chem. Chem. Phys.

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Three possible pathways for C-N bond breaking in methylamine have been investigated over clean Mo(100) and nitrogen atom-modified Mo(100) surfaces with a nitrogen coverage of 0.25 monolayer (ML) (N-Mo(100)) firstly, and the C-N bond breaking following the intramolecular hydrogen transfer from the CH3 to NH2 is excluded owing to the high barriers. Then methylamine decomposition starting with C-H, N-H, and C-N scission over the nitrogen atom-modified Mo(100) surface with a nitrogen coverage of 0.5 ML (2N-Mo(100)) has been systematically investigated, and the decomposition network has been mapped out. The thermochemistry and energy barriers for all the elementary steps, starting with C-H, N-H, and C-N scission, and sequential reactions from the resulting intermediates, are presented here. The most likely decomposition path is H3CNH2→ H2CNH2 + H → HCNH2 + H + H → CNH2 + H + H + H → C + NH2 + H + H + H → C + NH3 + H2→ C + NH3(g) + H2(g). For the decomposition reactions involved in the likely decomposition path, there is a linear relationship between the energy of transition state and the energy of final state. For the reverse processes of the dehydrogenation of CH, NH, NH2, it is found that there is a linear relationship between the barrier and the valency of A (A[double bond, length as m-dash]C, N, and NH).

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Temperature-programmed reaction of methylamine on the Ni{100} surface

Cited by 23 publications

References 0 publications

Aniline Adsorption, Hydrogenation, and Hydrogenolysis on the Ni(100) Surface

Aniline Adsorption, Hydrogenation, and Hydrogenolysis on the Ni(100) Surface

Adsorption and decomposition of methylamine on a Pt(100) surface: a density functional theory study

Decomposition of methylamine on nitrogen atom modified Mo(100): a density functional theory study

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