Characterization of Carbon Surface Chemistry by Combined Temperature Programmed Desorption with in Situ X-ray Photoelectron Spectrometry and Temperature Programmed Desorption with Mass Spectrometry Analysis

2012 ◽  
Vol 84 (5) ◽  
pp. 2147-2153 ◽  
Author(s):  
Patrice Brender ◽  
Roger Gadiou ◽  
Jean-Christophe Rietsch ◽  
Philippe Fioux ◽  
Joseph Dentzer ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Surface Chemistry ◽  
Temperature Programmed Desorption ◽  
Mass Spectrometry Analysis ◽  
Carbon Surface ◽  
X Ray ◽  
Spectrometry Analysis ◽  
Temperature Programmed

scholarly journals In-Exchanged CHA Zeolites for Selective Dehydrogenation of Ethane: Characterization and Effect of Zeolite Framework Type

Catalysts ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 807
Author(s):  
Zen Maeno ◽  
Xiaopeng Wu ◽  
Shunsaku Yasumura ◽  
Takashi Toyao ◽  
Yasuharu Kanda ◽  
...  
Keyword(s):  
Active Sites ◽  
Temperature Programmed Desorption ◽  
X Ray Diffraction ◽  
Zeolite Framework ◽  
X Ray ◽  
Catalytic Activities ◽  
Ethane Dehydrogenation ◽  
Temperature Programmed

In this study, the characterization of In-exchanged CHA zeolite (In-CHA (SiO2/Al2O3 = 22.3)) was conducted by in-situ X-ray diffraction (XRD) and ammonia temperature-programmed desorption (NH3-TPD). We also prepared other In-exchanged zeolites with different zeolite structures (In-MFI (SiO2/Al2O3 = 22.3), In-MOR (SiO2/Al2O3 = 20), and In-BEA (SiO2/Al2O3 = 25)) and different SiO2/Al2O3 ratios (In-CHA(Al-rich) (SiO2/Al2O3 = 13.7)). Their catalytic activities in nonoxidative ethane dehydrogenation were compared. Among the tested catalysts, In-CHA(Al-rich) provided the highest conversion. From kinetic experiments and in-situ Fourier transform infrared (FTIR) spectroscopy, [InH2]+ ions are formed regardless of SiO2/Al2O3 ratio, serving as the active sites.

scholarly journals Liquid chromatography–mass spectrometry analysis of dyes formed by in situ oxidative methods then purified by absorption and extraction from hair wefts

2020 ◽  
pp. 174751982097862
Author(s):  
M John Plater ◽  
Andrea Raab
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Complex Mixture ◽  
Ammonium Salts ◽  
Mass Spectrometry Analysis ◽  
Liquid Chromatography Mass Spectrometry ◽  
Spectrometry Analysis ◽  
Chromatography Mass Spectrometry ◽  
Didecyldimethylammonium Chloride

The dye mixtures formed from three commercial hair colour formers were purified by absorption onto human hair wefts, washed and dried, extracted with dichloromethane:trifluoroacetic acid (75:25) and then analysed by liquid chromatography–mass spectrometry. Only 1–2 dyes were identified from each complex mixture of commercial aromatic amines along with a broad UV absorption mainly consisting of mixtures of quaternary ammonium salts from shampoos and some surfactants. Mecetronium ethyl sulfate and didecyldimethylammonium chloride were the main ammonium salts.

Quantitative In Situ Mass Spectrometry Analysis of Mannitol Decomposition Products under Hydrothermal Conditions

2017 ◽  
Vol 31 (10) ◽  
pp. 10866-10873
Author(s):  
Pattasuda Duangkaew ◽  
Shuhei Inoue ◽  
Tsunehiro Aki ◽  
Yutaka Nakashimada ◽  
Yoshiko Okamura ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Mass Spectrometry Analysis ◽  
Hydrothermal Conditions ◽  
Decomposition Products ◽  
Spectrometry Analysis

scholarly journals Hydrogenative Cyclization of Levulinic Acid to γ-Valerolactone with Methanol and Ni-Fe Bimetallic Catalysts

Catalysts ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1096
Author(s):  
Ligang Luo ◽  
Xiao Han ◽  
Qin Zeng
Keyword(s):  
Photoelectron Spectroscopy ◽  
Levulinic Acid ◽  
Hydrogen Donor ◽  
Effect Of Temperature ◽  
X Ray ◽  
Transmission Electron ◽  
Ft Ir ◽  
Temperature Programmed

A series of Ni-Fe/SBA-15 catalysts was prepared and tested for the catalytic hydrogenation of levulinic acid to γ-valerolactone, adopting methanol as the only hydrogen donor, and investigating the synergism between Fe and Ni, both supported on SBA-15, towards this reaction. The characterization of the synthesized catalysts was carried out by XRD (X-ray powder diffraction), TEM (transmission electron microscopy), H2-TPD (hydrogen temperature-programmed desorption), XPS (X-ray photoelectron spectroscopy), and in situ FT-IR (Fourier transform–infrared spectroscopy) techniques. H2-TPD and XPS results have shown that electron transfer occurs from Fe to Ni, which is helpful both for the activation of the C=O bond and for the dissociative activation of H2 molecules, also in agreement with the results of the in situ FT-IR spectroscopy. The effect of temperature and reaction time on γ-valerolactone production was also investigated, identifying the best reaction conditions at 200 °C and 180 min, allowing for the complete conversion of levulinic acid and the complete selectivity to γ-valerolactone. Moreover, methanol was identified as an efficient hydrogen donor, if used in combination with the Ni-Fe/SBA-15 catalyst. The obtained results are promising, especially if compared with those obtained with the traditional and more expensive molecular hydrogen and noble-based catalysts.

scholarly journals Identification of sugars and phenolic compounds in honey powders with the use of GC–MS, FTIR spectroscopy, and X-ray diffraction

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Katarzyna Kozłowicz ◽  
Renata Różyło ◽  
Bożena Gładyszewska ◽  
Arkadiusz Matwijczuk ◽  
Grzegorz Gładyszewski ◽  
...  
Keyword(s):  
Phenolic Compounds ◽  
Ftir Spectroscopy ◽  
Mass Spectrometry Analysis ◽  
Gas Chromatography Mass Spectrometry ◽  
Coumaric Acid ◽  
X Ray Diffraction ◽  
Phenyllactic Acid ◽  
X Ray ◽  
Spectrometry Analysis

Abstract This work aimed at the chemical and structural characterization of powders obtained from chestnut flower honey (HFCh) and honey with Inca berry (HBlu). Honey powders were obtained by spray drying technique at low temperature (80/50 °C) with dehumidified air. Maltodextrin (DE 15) was used as a covering agent. The isolation and evaluation of phenolic compounds and sugars were done by gas chromatography–mass spectrometry analysis. Scanning electron microscopy, Fourier-transform infrared (FTIR) spectroscopy, and X-ray diffraction were performed to determine the morphology of the studied honey powders. The obtained results showed that the content of simple sugars amounted to 72.4 and 90.2 g × 100 g−1 in HFCh and HBlu, respectively. Glucose was found to be the dominant sugar with a concentration of 41.3 and 51.6 g × 100 g−1 in HFCh and HBlu, respectively. 3-Phenyllactic acid and ferulic acid were most frequently found in HFCh powder, whereas m-coumaric acid, benzoic acid, and cinnamic acid were the most common in HBlu powder. The largest changes in the FTIR spectra occurred in the following range of wavenumbers: 3335, 1640, and below 930 cm−1. The X-ray diffraction profiles revealed wide peaks, suggesting that both honey powders are amorphous and are characterized by a short-range order only.

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