Determination of Mesopores Diameters in Porous Solids from Adsorption Measurements – Criticisms and Suggestions

1988 ◽  
pp. 223-232 ◽  
Author(s):  
L. Bonnetain ◽  
J.L. Ginoux ◽  
M. Cabedo
Keyword(s):  
Porous Solids

Diffusion of Gases in Porous Solids. I. Theoretical Background and Experimental Method

1974 ◽  
Vol 52 (15) ◽  
pp. 2684-2691 ◽  
Author(s):  
K. R. Weller ◽  
N. S. Stenhouse ◽  
Harry Watts
Keyword(s):  
Diffusion Coefficients ◽  
Experimental System ◽  
Theoretical Background ◽  
Porous Solids ◽  
Diffusion Cell ◽  
Improved Method ◽  
Method Of Calculation ◽  
The Past ◽  
Concentration Changes

In the past, some authors have not defined the diffusion coefficient appropriate to their experimental system, consequently, valuable data have been lost. We discuss the various diffusion coefficients referred to all possible frames of reference in relation to the choice of a suitable experimental system for the determination of gaseous diffusion coefficients in porous media. A modified Ney and Armistead type diffusion cell is described with an improved method of calculation of results from continuously monitored concentration changes in the diffusion cell.

scholarly journals Structure and Stability of Gas Adsorption Complexes in Periodic Porous Solids as Studied by VTIR Spectroscopy: An Overview

2020 ◽  
Vol 10 (23) ◽  
pp. 8589
Author(s):  
Montserrat R. Delgado
Keyword(s):  
Gas Adsorption ◽  
Variable Temperature ◽  
Spectroscopic Technique ◽  
Porous Solids ◽  
Large Temperature ◽  
Adsorption Complexes ◽  
The Stability ◽  
Standard Enthalpy Change

Variable-temperature infrared (VTIR) spectroscopy is an instrumental technique that enables structural characterization of gas-solid adsorption complexes by analysis of meaningful vibrational modes, and simultaneous determination of the standard enthalpy change (ΔH0) involved in the gas adsorption process, which allows one to quantify the stability of the corresponding complex. This is achieved by a van’t Hoff analysis of a set of IR spectra recorded over a sufficiently large temperature range. Herein, the use of this versatile spectroscopic technique is demonstrated by reviewing its application to the study of carbon monoxide, carbon dioxide and dinitrogen adsorption on several (alkaline) zeolites, which can be regarded as the archetype of periodic porous solids.

scholarly journals Non-Linear Enthalpy-Entropy Correlation for Nitrogen Adsorption in Zeolites

Molecules ◽  
2018 ◽  
Vol 23 (11) ◽  
pp. 2978 ◽  
Author(s):  
Montserrat Delgado ◽  
Carlos Arean
Keyword(s):  
Infrared Spectroscopy ◽  
Linear Correlation ◽  
Variable Temperature ◽  
Nitrogen Adsorption ◽  
Porous Solids ◽  
Separation And Purification ◽  
N2 Adsorption ◽  
Adsorption Enthalpy ◽  
Non Linear

The thermodynamics of dinitrogen adsorption in faujasite-type zeolites, Na-Y, Ca-Y and Sr-Y, were investigated by means of variable-temperature infrared spectroscopy, a technique that affords determination of the standard adsorption enthalpy (ΔH0) and entropy (ΔS0) from an analysis of the IR spectra recorded over a range of temperatures. The results obtained, taken together with previously reported values for N2 adsorption on protonic zeolites, revealed a non-linear correlation between ΔH0 and ΔS0. Implications of such a correlation for gas separation and purification by adsorption in porous solids are highlighted.

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