Adsorption of nitrogen oxide on a V2O5/Al2O3 catalyst

1985 ◽  
Vol 50 (6) ◽  
pp. 1259-1267 ◽  
Author(s):  
Zdeněk Sobalík ◽  
Vladimír Pour ◽  
Ludmila A. Sokolova ◽  
Olga V. Nevskaya ◽  
Nina M. Popova
Keyword(s):  
Infrared Spectroscopy ◽  
Nitrogen Oxide ◽  
Elevated Temperatures ◽  
Volume Ratio ◽  
Temperature Programmed Desorption ◽  
Adsorption And Desorption ◽  
Adsorption Of Nitrogen ◽  
Order Of Magnitude ◽  
Temperature Programmed ◽  
Al2o3 Catalyst

The adsorption and desorption of nitrogen oxide on oxidized and reduced V2O5/Al2O3 catalysts (14.7% (m/m) V2O5) were studied by gravimetry, infrared spectroscopy, and temperature programmed desorption measurements. On the reduced catalyst, NO is adsorbed giving rise to mono- and dinitrosyls which exhibit infrared bands at 1 690, 1 760, 1 820, and 1 895 cm-1. A band also appears at 1 220 cm-1 corresponding to nitrite structures. The ratio between the nitrosyl and nitrite structures is approximately 4 : 1. Desorption at elevated temperatures is associated with the evolution of NO and N2O in a volume ratio of 10 : 1. On the oxidized catalyst the adsorption occurs to an extent at least two order of magnitude lower and no nitrosyls are formed.

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.

The Characterization of Hydrocarbon Intermediates in H-ZSM-5

1987 ◽  
Vol 111 ◽  
Author(s):  
T. J. Gricus Kofke ◽  
R. J. Gorte ◽  
W. E. Farneth
Keyword(s):  
Infrared Spectroscopy ◽  
Thermogravimetric Analysis ◽  
Acid Site ◽  
Adsorbed Molecule ◽  
Temperature Programmed Desorption ◽  
Acid Sites ◽  
Adsorption State ◽  
Brönsted Acid ◽  
Temperature Programmed

AbstractWe have examined the adsorption of simple alcohols and 2-propanamine on H-ZSM-5 zeolites with Si/Al2 ratios between 38 and 520. Thermogravimetric analysis (TGA) demonstrated that most of the molecules display a clearly defined adsorption state corresponding to a coverage of one molecule per Al site. Temperature programmed desorption (TPD) and transmission infrared spectroscopy results for each of the molecules in this 1:1 adsorption state are consistent with adsorption being due to the transfer of a proton from the zeolite to the adsorbed molecule. These results provide additional evidence that carefully prepared H-ZSM-5 is a Bronsted acid, with one acid site per framework Al atom, in which all of the acid sites are identical in strength.

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.

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