A Model Calculation for the Isomerization and Decomposition of Chemisorbed HCN on the Si(100)‐2×1 Surface

Bacalzo-Gladden, F.; Musaev, Djamaladdin G.; Lin, Ming‐Chang

doi:10.1002/jccs.199900055

Cited by 11 publications

(17 citation statements)

References 33 publications

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“…This shift in binding energy is attributed to the increasing presence of atomic C and N surface species formed from partial decomposition of the surface CN groups. The initial decomposition of the CN groups at 473 K is similar to that found for ICN 1 and other comparable systems . As the annealing temperature is further increased, the C 1s and N 1s peaks continue to broaden and shift toward lower energies as the concentration of adsorbed atomic C and N species increases with the simultaneous decrease in the concentration of adsorbed CN.…”

Section: Resultssupporting

confidence: 74%

“…The initial decomposition of the CN groups at 473 K is similar to that found for ICN 1 and other comparable systems. 4 As the annealing temperature is further increased, the C 1s and N 1s peaks continue to broaden and shift toward lower energies as the concentration of adsorbed atomic C and N species increases with the simultaneous decrease in the concentration of adsorbed CN. Finally at around 873 K, the C 1s and N 1s peaks indicate only the atomic species with binding energies of 283 and 398 eV, respectively, remain on the Si(100) surface.…”

Section: Resultsmentioning

confidence: 98%

“…8 UPS Low-Temperature Adsorption. The ground state of the iodide, bromide, and chloride cyanogen halides in the gas phase has been determined to be a 1 Σ + state with a (1σ) 2 (2σ) 2 -(3σ) 2 (1π) 4 (4σ) 2 (2π) 4 electron configuration for the valence electrons. [17][18][19][20][21][22][23] An important aspect of the chemical binding between the halogen and the CN group is the overlap between the atomic p orbital centered on the halogen and the π-system of the CN group.…”

Section: Resultsmentioning

confidence: 99%

“…Lu and Lin have recently reviewed reaction of C, N, and O containing molecules with the Si(100) surface . In particular, Lin and co-workers − have studied hydrogen cyanide (HCN) and cyanogen (C 2 N 2 ), on Si(100) and Si(111) surfaces. Bu and Lin have also studied another similar compound, s-triazine ((HCN) 3 ), on the Si(100) surface .…”

Section: Introductionmentioning

confidence: 99%

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Adsorption Chemistry of Cyanogen Bromine and Cyanogen Chlorine on Silicon(100)

et al. 2003

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The adsorption and decomposition of cyanogen halides, XCN (X ) Br, Cl), on Si(100) is investigated utilizing X-ray photoelectron spectroscopy (XPS) and ultraviolet photoelectron spectroscopy (UPS). For submonolayer exposures, XPS indicates that the CN triple bond of XCN remains intact upon adsorption at 100 K. The UPS spectrum contains two peaks assigned to the π-electrons in the CN triple bond. The splitting indicates that some fraction of the XCN molecules adsorbs molecularly at low temperature. XPS analyses of the C 1s photoelectron peak following submonolayer exposure at low temperature suggest a greater fraction of BrCN (60%) adsorbs molecularly than ClCN (40%). XPS and UPS measurements at room temperature show that the X-CN bond breaks, while the CN bond remains intact during room-temperature adsorption on Si(100). Thus, the UPS spectrum of XCN adsorbed at room temperature on Si(100) contains a peak at 6.0 eV due to the unperturbed π electrons of the CN species. Upon annealing a CN-saturated Si(100) surface to higher temperatures, the UPS spectra indicate that the CN bond remains intact until approximately 700 K. Simultaneous changes in the C 1s and N 1s photoelectron peaks are consistent with the idea that CN bond cleavage is correlated with silicon carbide and nitride formation. These results are compared with a previous study of ICN adsorption on Si(100).

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Section: Resultssupporting

confidence: 74%

Section: Resultsmentioning

confidence: 98%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Adsorption Chemistry of Cyanogen Bromine and Cyanogen Chlorine on Silicon(100)

et al. 2003

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“…For HCN, a stable side-on structure surrounded by transition state barriers larger than the adsorption energy is predicted. 7,17 The stronger HC bond with respect to the HSi bond gives the analogous HCN structure greater stability than that of XCN2. For XCN2, a low barrier reaction pathway driven by the formation of a strong XSi bond destabilizes this structure.…”

Section: Resultsmentioning

confidence: 99%

Adsorption and Decomposition Pathways of Cyanogen Halides on Si(100)−(2×1)

2003

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The adsorption and surface reactions of ICN, BrCN, and ClCN on the Si(100)-(2×1) surface are studied using ab initio quantum calculations on single-and triple-dimer silicon clusters. These cyanogen halides can physisorb into an end-on molecular species that is bound through the N to the Si cluster via a dative bond. The adsorption energy of this dative bonded species is found to depend on the cluster size. This species can further react to form a side-on intermediate by reacting across the Si-dimer bond or can lose the halide group and form an adsorbed CN species. The adsorbed CN group can have N-bonded and C-bonded orientations, with the C-bonded configuration having the lowest energy. The side-on intermediate can react to an additional intermediate species in which the halide-carbon bond is broken and the C end of the CN group inserts into the Si-dimer bond. An adsorbed CN group can subsequently form from this insertion species. Once the reaction proceeds from the dative bonded species, no significant barriers are present and the lowest energy structure is predicted to form in agreement with experimental studies.

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Probing hydrogen–nitrogen chemistry: A theoretical study of important reactions in NxHy, HCN and HNCO oxidation

2020

International Journal of Hydrogen Energy

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As an indirect storage medium of hydrogen, ammonia (NH3) has drawn significant attention from academia and industry. Understanding nitrogen combustion chemistry is a major challenge in applying ammonia for converting chemical energy to thermal energy. Diazene (N2H2), diazenyl radical (NNH), amidogen radical (NH2), hydrogen cyanide (HCN) and isocyanic acid (HNCO) are the crucial intermediate species in the combustion of NH3 or its mixtures with other hydrocarbons. In light of that, this study provides advanced theoretical treatment of 14 important reactions in the oxidation of these intermediates, including isomerization, dissociation and abstraction reactions. The rate constants of all these reactions, and the temperature-dependent thermochemistry of the species involved in the reactions, were calculated utilizing high level quantum chemical methods. Ro-vibrational properties of the reactants, products and stationary points were determined at the M06-2X/6-311++G(d,p) level of theory. Coupled cluster (CCSD(T)) methods were employed, with two large basis sets (cc-pVTZ and cc-pVQZ), and complete basis set of extrapolation techniques to compute the energies of the resulting geometries. All calculated results were compared with experimental and theoretical results in the literature. Finally, the implications of this work for combustion modelling were investigated, and the simulated species' profiles of HCN and HNCO demonstrated the influence of the updated rate coefficients on kinetic model predictions.

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A Model Calculation for the Isomerization and Decomposition of Chemisorbed HCN on the Si(100)‐2×1 Surface

Cited by 11 publications

References 33 publications

Adsorption Chemistry of Cyanogen Bromine and Cyanogen Chlorine on Silicon(100)

Adsorption Chemistry of Cyanogen Bromine and Cyanogen Chlorine on Silicon(100)

Adsorption and Decomposition Pathways of Cyanogen Halides on Si(100)−(2×1)

Probing hydrogen–nitrogen chemistry: A theoretical study of important reactions in NxHy, HCN and HNCO oxidation

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