Propane and propane–water interactions: a study at cryogenic temperatures

2018 ◽  
Vol 20 (3) ◽  
pp. 1838-1847 ◽  
Author(s):  
Jyotirmoy Ghosh ◽  
Annapoorani Kobuvayur Hariharan ◽  
Radha Gobinda Bhuin ◽  
Rabin Rajan J. Methikkalam ◽  
Thalappil Pradeep
Keyword(s):  
Mass Spectrometry ◽  
Phase Transition ◽  
Infrared Spectroscopy ◽  
Ultrahigh Vacuum ◽  
Temperature Programmed Desorption ◽  
Water Mixture ◽  
Cryogenic Temperatures ◽  
Desorption Mass Spectrometry ◽  
Reflection Absorption Infrared Spectroscopy ◽  
Temperature Programmed

The phase transition of solid propane and a propane–water mixture under ultrahigh vacuum has been investigated using reflection absorption infrared spectroscopy (RAIRS) and temperature-programmed desorption mass spectrometry (TPD-MS).

scholarly journals Thermal Transformation of Caffeic Acid on the Nanoceria Surface Studied by Temperature Programmed Desorption Mass-Spectrometry, Thermogravimetric Analysis and FT–IR Spectroscopy

2019 ◽  
Vol 3 (1) ◽  
pp. 34 ◽  
Author(s):  
Nataliia Nastasiienko ◽  
Borys Palianytsia ◽  
Mykola Kartel ◽  
Mats Larsson ◽  
Tetiana Kulik
Keyword(s):  
Mass Spectrometry ◽  
Thermogravimetric Analysis ◽  
Cerium Dioxide ◽  
Temperature Programmed Desorption ◽  
Hydroxyl Groups ◽  
Surface Complexes ◽  
Desorption Mass Spectrometry ◽  
Ft Ir ◽  
Temperature Programmed ◽  
Ft Ir Spectroscopy

The studies of pyrolysis of caffeic acid (CA) and its surface complexes is important for the development of technologies of heterogeneous catalytic pyrolysis of plant- and wood- based renewable biomass components. In this work, the structure and thermal transformations of the surface complexes of CA on the surface of nanoceria were investigated using Fourier transform–infrared (FT–IR) spectroscopy, thermogravimetric analysis (TGA) and temperature-programmed desorption mass spectrometry (TPD MS). It was found that CA on the surface of cerium dioxide forms several types of complexes: bidentate carboxylates, monodentate carboxylates and complexes formed as a result of interaction with phenolic hydroxyl groups. This is due to the ability of nanosized cerium dioxide to generate basic hydroxyl groups that can deprotonate phenolic groups to form phenolates on the surface. The main pyrolysis products were identified. The possible ways of forming 3,4-dihydroxyphenylethylene, acetylene carboxylic acid, pyrocatechol and phenol from surface complexes of CA were suggested. It was established that on the nanoceria surface effectively occur the decarboxylation, decarbonylation, and dehydration reactions of the CA, which are the desirable processes in biomass conversion technologies.

Adsorption and reaction pathways of a chiral probe molecule, S-glycidol on a Pd(111) surface

2015 ◽  
Vol 5 (2) ◽  
pp. 738-742 ◽  
Author(s):  
Mausumi Mahapatra ◽  
Wilfred T. Tysoe
Keyword(s):  
Infrared Spectroscopy ◽  
Reaction Pathway ◽  
Temperature Programmed Desorption ◽  
Reaction Pathways ◽  
Probe Molecule ◽  
Reflection Absorption Infrared Spectroscopy ◽  
Temperature Programmed

The chemistry of S-glycidol is studied on a Pd(111) surface using temperature-programmed desorption and reflection–absorption infrared spectroscopy to explore its suitability as a chiral probe molecule and to follow its reaction pathway.

KINETIC AND REACTIVE PROPERTIES OF ETHYLENE ON CLEAN AND HYDROGEN-COVERED Pd(111)

2003 ◽  
Vol 10 (06) ◽  
pp. 909-916 ◽  
Author(s):  
L. BURKHOLDER ◽  
D. STACCHIOLA ◽  
W. T. TYSOE
Keyword(s):  
Activation Energy ◽  
Infrared Spectroscopy ◽  
Temperature Programmed Desorption ◽  
Molecular Adsorption ◽  
Lateral Interactions ◽  
Ethylene Adsorption ◽  
Reflection Absorption Infrared Spectroscopy ◽  
Temperature Programmed ◽  
Ethane Formation ◽  
Reactive Properties

Several molecular adsorption states are identified following ethylene adsorption on clean and hydrogen-covered Pd(111) using temperature-programmed desorption (TPD) and reflection absorption infrared spectroscopy (RAIRS). Di-σ-bonded ethylene forms on clean Pd(111) desorbing with an activation energy of 80 kJ/mol at low coverages. The strong intermolecular lateral interactions considerably reduce the desorption temperature at higher coverages. Π-bonded ethylene is formed on hydrogen-covered Pd(111), where the proportion of π-bonded species increases with hydrogen coverage. This species converts to the more stable di-σ-bonded species on heating. Ethane formation is detected in TPD from hydrogen-precovered Pd(111), which is predominantly formed by reaction with π-bonded ethylene.

scholarly journals Temperature-Programmed Desorption Mass Spectrometry (TPDMS) of Dispersed Oxides

1996 ◽  
Vol 14 (5) ◽  
pp. 301-317 ◽  
Author(s):  
Valeriy A. Pokrovskiy
Keyword(s):  
Mass Spectrometry ◽  
Silica Surface ◽  
Cobalt Atom ◽  
Phosphorous Acid ◽  
Temperature Programmed Desorption ◽  
Biologically Active ◽  
Analytical Treatment ◽  
Desorption Mass Spectrometry ◽  
Pyrogenic Silica ◽  
Temperature Programmed

Temperature-programmed desorption mass spectrometry (TPDMS) is discussed with reference to studies of modified pyrogenic oxides. Simple theoretical models are presented in order to allow an approximate analytical treatment of TPDMS data. The ‘unimolecular’ decomposition of alkoxide groups was studied. The rate constants of the reactions were derived from TPDMS measurements. The kinetics of thermal transformations of phosphorous and phosphoric acids on a pyrogenic silica surface were investigated by TPDMS. Oxidation–reduction reactions in samples containing phosphorous acid resulted in the removal of molecular phosphorus (P4). Two stages of phosphorus evolution were observed which were attributed to the disproportion of phosphorus in the surface monolayer (high-temperature stage) and in the bulk layers (low-temperature stage). The biologically active samples obtained by adsorption of cyanocobalamine, glucose and raffinose on ultrafine oxide surfaces were studied via a combination of temperature-programmed desorption and solid-state thermal analysis mass spectrometry (TPD/TA MS). The role of the charged cobalt atom and of the propionamide and benzimide groups in the adsorption mechanism is discussed. It was shown that the adsorption of cyanocobalamine on the silica surface transformed the propionamide group to a weakly bound form. TPD/TA MS data were obtained confirming the stable adsorption of glucose and raffinose on an ultrafine pyrogenic silica surface modified by amino groups.

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