Investigation of rehydration of pyrogenic silica by temperature-programmed desorption method

1991 ◽  
Vol 27 (1) ◽  
pp. 89-93 ◽  
Author(s):  
V. V. Brei ◽  
Yu. I. Gorlov ◽  
A. A. Chuiko
Keyword(s):  
Temperature Programmed Desorption ◽  
Pyrogenic Silica ◽  
Temperature Programmed ◽  
Desorption Method

Investigation of Oxygen Interaction with a Pt−Rh/Al2O3Catalyst by a Differential Temperature-Programmed Desorption Method

Langmuir ◽  
2003 ◽  
Vol 19 (22) ◽  
pp. 9266-9270 ◽  
Author(s):  
J. J. Lecomte ◽  
S. Haydar ◽  
P. Granger ◽  
L. Leclercq ◽  
G. Leclercq ◽  
...  
Keyword(s):  
Temperature Programmed Desorption ◽  
Temperature Programmed ◽  
Desorption Method ◽  
Oxygen Interaction

Complex Catalysts for Direct Synthesis of Dimethyl Ether From Synthesis Gas. Part II. The Interaction of the Process Reactants and Products with the Catalyst Surfaces

2013 ◽  
Vol 872 ◽  
pp. 23-29
Author(s):  
Natalia I. Kosova ◽  
Irina A. Kurzina ◽  
Larisa N. Kurina
Keyword(s):  
Dimethyl Ether ◽  
Direct Synthesis ◽  
Temperature Programmed Desorption ◽  
Main Process ◽  
Methanol Dehydration ◽  
Mass Spectrometry Detection ◽  
Temperature Range ◽  
Temperature Programmed ◽  
Desorption Method ◽  
Synthesis Of Dimethyl Ether

The mechanism of the Н2, СО, СО2, СН3ОН, (CH3)2O interaction with the surfaces of CuO/ZnO/Al2O3and γ-Al2O3was investigated using temperature-programmed desorption method with mass spectrometry detection. It was shown that desorption of the main process components takes place in the temperature range between 373 and 673 K, which corresponds to the temperature range for catalytic studies. Methanol dehydration takes place over the surface of γ-Al2O3catalyst with formation of dimethyl ether at Тmax= 553 К, which is the optimal temperature for synthesis of dimethyl ether from CO and H2over industrial catalysts with layered loadings. The desorption energies of the gases were calculated.

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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