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

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.

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REVERSIBILITY IN PHYSICAL ADSORPTION

Canadian Journal of Chemistry ◽

10.1139/v55-028 ◽

1955 ◽

Vol 33 (2) ◽

pp. 245-250 ◽

Cited By ~ 1

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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A Simple Approach to the 2D Mobile Adsorption of Gases on Heterogeneous Solid Surfaces Exhibiting Random Surface Topography

Adsorption Science & Technology ◽

10.1177/026361748900600105 ◽

1989 ◽

Vol 6 (1) ◽

pp. 35-51 ◽

Cited By ~ 3

Author(s):

W. Rudzinski ◽

J. Jagiello

Keyword(s):

Surface Topography ◽

Compressibility Factor ◽

Simple Approach ◽

Solid Surfaces ◽

Random Surface ◽

Heats Of Adsorption ◽

Adsorption Of Gases ◽

Mobile Adsorption ◽

Simple Equations ◽

Heterogeneous Solid

Based on a summation to infinity of the virial expansion for the 2D compressibility factor, simple equations have been developed for adsorption isotherms, and heats of adsorption, of 2D dense mobile films adsorbed on solid surfaces. They have subsequently been generalized for the presence of an external, randomly varying potential field, created by the random surface topography exhibited by heterogeneous solid surfaces.

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