Heats of Adsorption of Gases on Chromic Oxide at Low Temperatures*

1938 ◽  
Vol 60 (12) ◽  
pp. 2912-2922 ◽  
Author(s):  
Ralph A. Beebe ◽  
Dennis A. Dowden
Keyword(s):  
Low Temperatures ◽  
Chromic Oxide ◽  
Heats Of Adsorption ◽  
Adsorption Of Gases

Isosteric Heats of Adsorption of Gases and Vapors on a Microporous Carbonaceous Material

2018 ◽  
Vol 63 (8) ◽  
pp. 3107-3116 ◽  
Author(s):  
S. Hadi Madani ◽  
Francisco Rodríguez-Reinoso ◽  
Mark J. Biggs ◽  
Phillip Pendleton
Keyword(s):  
Carbonaceous Material ◽  
Heats Of Adsorption ◽  
Adsorption Of Gases

Variation of sticking probabilities with temperature and coverage, and desorption spectra for nitrogen on tungsten films

1967 ◽  
Vol 297 (1450) ◽  
pp. 321-335 ◽  
Keyword(s):  
Low Temperatures ◽  
Room Temperature ◽  
Continuous Distribution ◽  
Kcal Mole ◽  
Initial Value ◽  
Precursor State ◽  
Heats Of Adsorption ◽  
Sticking Probabilities ◽  
Increasing Temperature ◽  
Pressure Changes

From 78 to 150°K, and at coverages < 8 x 10 14 molecules/cm 2 , the sticking probability s of nitrogen on tungsten films (= 0·9) is independent of both temperature and coverage, whereas at temperatures above 150°K it is a function of both these variables. These results are interpreted in terms of a physically adsorbed precursor state with a heat of adsorption of ca . 3 kcal/mole. It is concluded that only a fraction of molecules colliding with the surface enter this state and that it is this fraction which determines the initial value of s at low temperatures. The decrease of s with increasing temperature above 150°K is a consequence of the inactivity of some planes, such as the (110), at the higher temperatures. Desorption spectra were obtained by warming films from 78°K to room temperature and recording the subsequent pressure changes as a function of time. From these data the distribution of site energies for the weakly held adsorbate (the αγ state) was evaluated, indicating a continuous distribution with heats of adsorption varying between 6 and 20 kcal/mole.

Heats of Adsorption at — 183°: Hydrogen on Chromic Oxide

1937 ◽  
Vol 59 (9) ◽  
pp. 1627-1629 ◽  
Author(s):  
Ralph A. Beebe ◽  
Horace M. Orfield
Keyword(s):  
Chromic Oxide ◽  
Heats Of Adsorption

scholarly journals The oxidation of copper and the reactions of hydrogen and carbon monoxide with copper oxide

1949 ◽  
Vol 197 (1050) ◽  
pp. 294-314 ◽  
Keyword(s):  
Carbon Monoxide ◽  
Cuprous Oxide ◽  
Room Temperature ◽  
Hydrogen Reduction ◽  
Metallic Copper ◽  
Conductivity Measurements ◽  
Heats Of Adsorption ◽  
Adsorption Of Gases ◽  
Conductivity Of Thin Films ◽  
Kinetics Of

An investigation has been made of the activation of copper by successive oxidation and reduction with hydrogen. Reduction with carbon monoxide causes deactivation of the surface. The heats of adsorption of carbon monoxide and oxygen and the heat liberated during the catalytic reaction of carbon monoxide and oxygen on a cuprous oxide film formed on metallic copper have been measured at room temperature. The kinetics of the reactions have been studied. The electrical conductivity of thin films of oxides has been measured during the reduction with hydrogen, and a study made of the process of embrittlement, whereby the surface is activated. The effect of the adsorption of gases on the conductivity of the Cu 2 O-CuO surface has been investigated. Oxygen enhances the conductivity and carbon monoxide and hydrogen depress it. The reaction between carbon monoxide and oxygen has been followed at room temperature by conductivity measurements and the results have been employed to interpret the nature of the adsorption, the kinetics of the reaction, and the deactivation of the surface by carbon monoxide.

REVERSIBILITY IN PHYSICAL ADSORPTION

1955 ◽  
Vol 33 (2) ◽  
pp. 245-250 ◽  
Author(s):  
E. L. Pace ◽  
K. S. Dennis ◽  
S. A. Greene ◽  
E. L. Heric
Keyword(s):  
Heat Capacity ◽  
Adsorption Isotherms ◽  
Physical Adsorption ◽  
Zero Point ◽  
Solid Surfaces ◽  
Heats Of Adsorption ◽  
Calorimetric Measurements ◽  
Adsorbed Phase ◽  
Adsorption Of Gases ◽  
Calorimetric Studies

The question of reversibility and equilibrium is considered in relation to the physical adsorption of gases on finely divided solid surfaces. Conclusions are drawn from calorimetric measurements of (1) adsorption isotherms, (2) integral, differential, and isosteric heats of adsorption, and (3) heat capacity of the adsorbed phase for surface coverages of the order of a monolayer or less. In line with the preceding, results are presented and discussed for calorimetric studies involving (1) heats of adsorption and heat capacities of methane adsorbed on rutile between 80 and 140°K., (2) heats of adsorption of argon on rutile between 60 and 90°K., and (3) the zero point entropy of krypton adsorbed on rutile at a coverage of about 0.57 of the monolayer capacity.

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