Identification of molecular adsorbates by LITD/FTMS: a breakthrough for surface chemistry

Land, Donald P.; Pettiette-Hall, C.L.; Hemminger, John C.; McIver, Robert T.

doi:10.1021/ar00002a003

Cited by 32 publications

(22 citation statements)

References 55 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The resultant rapid temperature jump causes the intact desorption of molecular adsorbates, even if slower heating rates would have resulted in a surface reaction. 52,54,62,69 The neutral molecules are then ionized by electron ionization (70 eV) and detected by Fourier transform mass spectrometry (FTMS). 54 The laser optics are controlled such that each laser pulse probes a different spot on the surface.…”

Section: Methodsmentioning

confidence: 99%

“…52,54,62,69 The neutral molecules are then ionized by electron ionization (70 eV) and detected by Fourier transform mass spectrometry (FTMS). 54 The laser optics are controlled such that each laser pulse probes a different spot on the surface. The use of FTMS to detect and identify the laser-desorbed species provides a complete mass spectrum from each laser pulse incident on the surface, with very good sensitivity.…”

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Pyridine Adsorption and Acid/Base Complex Formation on Ultrathin Films of γ-Al₂O₃on NiAl(100)

2003

Self Cite

View full text Add to dashboard Cite

Pyridine adsorption on NiAl(100) and ultrathin films of γ-Al 2 O 3 was studied using high-resolution electron energy loss spectroscopy (HREELS). Pyridine adsorbs on NiAl(100) with its molecular axis parallel to the surface plane at low coverages and with its molecular plane inclined more toward the surface normal at higher coverages. On the hydroxylated and nonhydroxylated thin films of γ-Al 2 O 3 , pyridine interacts with the coordinatively unsaturated Al 3+ cations via its nitrogen lone-pair electrons. Pyridine was also found to interact with the surface hydroxyl groups on the hydroxylated γ-Al 2 O 3 thin films, forming C 5 H 5 N-HO complexes. Complex formation causes the OH bond strength to decrease and the OH stretch vibration to shift from 3711 cm -1 , which is characteristic of uncomplexed, isolated OH, to lower frequency. At low coverages, pyridine only interacts with the more acidic surface OH groups, those located on 3-fold Al 3+ cation sites. This interaction forms a C 5 H 5 N-HO complex, which has an O-H stretch at 2920 cm -1 . As the coverage is increased, an additional C 5 H 5 N-HO complex is formed from an interaction between pyridine and the less acidic OH groups, which are bonded to 2 Al 3+ cations. The vibrational frequency for O-H stretch of this C 5 H 5 N-HO complex is 3150 cm -1 . As the intensities for the O-H stretches of the C 5 H 5 N-HO complexes increase, the intensity for the free O-H stretch at 3711 cm -1 decreases. The interaction with the surface hydroxyl groups is reversible, confirming that the observed shifts in the O-H stretching frequency result from the formation of weakly bonded acid-base complexes. While most of the pyridine desorbs from the γ-Al 2 O 3 thin films by 290 K, annealing the pyridine-dosed γ-Al 2 O 3 thin films to temperatures above 290 K, results in a small amount of pyridine dehydrogenation and the formation of surface OH groups with an O-H stretch at 3742 cm -1 .

show abstract

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Pyridine Adsorption and Acid/Base Complex Formation on Ultrathin Films of γ-Al₂O₃on NiAl(100)

2003

Self Cite

View full text Add to dashboard Cite

show abstract

“…[28][29][30] During LITD/FTMS, a single laser pulse rapidly heats (10 11 K/s) a 1-mm-diam spot on the sample, desorbing surface-bound species within the irradiated area. The rapid heating rate can access high-energy pathways and may result in desorption of otherwise thermally labile species before decomposition can occur.…”

Section: B Litd/ftmsmentioning

confidence: 99%

“…23,24 When coupled with FT mass spectrometry ͑FTMS͒, LITD has been shown to be an effective tool for the analysis of complex mixtures of molecular adsorbates, such as one finds during the course of surface-catalyzed reaction, and for the determination of kinetic parameters for surface processes. [25][26][27][28][29][30][31][32][33] Combined in a single UHV instrument, LITD/FTMS and FT-RAIRS would provide complementary information about the molecular nature of surface species. During LITD, a laser pulse thermally desorbs surface bound species as neutrals from the sample without substrate ablation.…”

Section: Introductionmentioning

confidence: 99%

An ultrahigh vacuum surface analysis instrument incorporating a Fourier transform mass spectrometer and a Fourier transform infrared spectrometer

Abdelrehim

Thornburg

Land

1997

Review of Scientific Instruments

Self Cite

View full text Add to dashboard Cite

Articles you may be interested inDevelopment of new in situ observation system for dynamic study of lubricant molecules on metal friction surfaces by two-dimensional fast-imaging Fourier-transform infrared-attenuated total reflection spectrometer Rev. Sci. Instrum. 79, 123702 (2008); 10.1063/1.2987685 Photomodulated infrared spectroscopy by a step-scan Fourier transform infrared spectrometer A molecular beam/surface spectroscopy apparatus for the study of reactions on complex model catalysts Rev. Sci. Instrum. 71, 4395 (2000)

show abstract

“…LITD uses a lower power density to heat the surface and desorb neutral molecules, requiring the use of a separate ionization source, but preventing the fragmentation and molecular rearrangements that have been observed with LA . Sufficiently, low laser power densities will cause desorption of surface species by thermal excitation, but will be insufficient to cause bond scission of the main soot agglomeration . Power densities over a certain threshold, on the other hand, will cause bond scission, resulting in the increased appearance of fragmentation products .…”

mentioning

confidence: 99%

The Effect of Laser Power Density on the Observed Products of Combustion of Gasoline Using Laser‐Induced Thermal Desorption with Fourier Transform Mass Spectrometry

Hutches

Wang

Land

2012

Journal of Forensic Sciences

Self Cite

View full text Add to dashboard Cite

Layered soot analysis is explored as a potential indicator of gasoline in a fire. Current techniques lack the ability to analyze layered soot samples without the destruction of the layered information. Laser-induced thermal desorption (LITD) coupled with Fourier transform mass spectrometry (FTMS) is developed as a method for analyzing soot samples. Samples of soot on glass from the free combustion of gasoline are collected and analyzed using LITD-FTMS, and the effect of power density on the resulting chemical profile is reported. At higher power densities, a distribution of low m/z products is observed. At lower power densities, the products observed shift to higher molecular weights, with peaks attributable to the tropyllium ion, naphthalene, and pyrene. Results at low power densities suggest that LITD-FTMS is a viable method for the analysis of soot, with potential for use with layered soot samples. Peaks potentially useful for fuel differentiation of gasoline are identified.

show abstract

Identification of molecular adsorbates by LITD/FTMS: a breakthrough for surface chemistry

Cited by 32 publications

References 55 publications

Pyridine Adsorption and Acid/Base Complex Formation on Ultrathin Films of γ-Al₂O₃on NiAl(100)

Pyridine Adsorption and Acid/Base Complex Formation on Ultrathin Films of γ-Al₂O₃on NiAl(100)

An ultrahigh vacuum surface analysis instrument incorporating a Fourier transform mass spectrometer and a Fourier transform infrared spectrometer

The Effect of Laser Power Density on the Observed Products of Combustion of Gasoline Using Laser‐Induced Thermal Desorption with Fourier Transform Mass Spectrometry

Contact Info

Product

Resources

About

Identification of molecular adsorbates by LITD/FTMS: a breakthrough for surface chemistry

Cited by 32 publications

References 55 publications

Pyridine Adsorption and Acid/Base Complex Formation on Ultrathin Films of γ-Al2O3on NiAl(100)

Pyridine Adsorption and Acid/Base Complex Formation on Ultrathin Films of γ-Al2O3on NiAl(100)

An ultrahigh vacuum surface analysis instrument incorporating a Fourier transform mass spectrometer and a Fourier transform infrared spectrometer

The Effect of Laser Power Density on the Observed Products of Combustion of Gasoline Using Laser‐Induced Thermal Desorption with Fourier Transform Mass Spectrometry

Contact Info

Product

Resources

About

Pyridine Adsorption and Acid/Base Complex Formation on Ultrathin Films of γ-Al₂O₃on NiAl(100)

Pyridine Adsorption and Acid/Base Complex Formation on Ultrathin Films of γ-Al₂O₃on NiAl(100)