Measurement of Adsorption Isotherms of Reactive Gases by a Gas Chromatographic Technique

Methanol Vapor Adsorption on Silica and Soda‐Lime‐Silica Glass

“…This behavior indicates the absence of an appreciable n u m l w of micropores, which could also have a largc effect on thc(cmergies of adsorption. Assuming a cross sectional area of 30 x' for the adsorbed methanol moleciile,4 combination of the data in ' Table I1 with the measured nitrogen specific surface arca of 3000 cm2/g for the adsorbents indicates that more than 10 to 20(% of thc apparent surface areas of the adsorbents would have to be contained in micropores if the measured heats of adsorption are controlled by this factor, because the isosteric heats did not vary over the range of adsorbent coverages encountered. Such a large number of micropores would slion-itself in the curvature of benzene adsorption isotherms on tlic adsor1)ents.l The BET constant (which is an expression of isotherm curvature) was 10.0 for the silica grains and 9.7 for the glass grains after the respective adsorbents had been dcgassed at 200°C.…”

Applications of Gas Chromatography in Catalysis

“…Recently, a rapid gas chromatographic method has been proposed by Fedorov et al (1968) for the determination of desorption isotherms by gradual displacement of adsorbed nitrogen with a nonadsorbable carrier gas-e.g., heliumunder dynamic conditions. The methods presented above have been employed by several investigators (Schay et ah, 1957(Schay et ah, , 1958; Afanasev and Rubinstein, 1958;Toth and Graf, 1960;Roginskii et al, 1960;Eberly, Jr., and Kimberlin, Jr., 1961; Oldenkamp and Houghton, 1963; Owens et al, 1964;Brooks, 1965;Saint, 1965;Feltl et al, 1965;Gavrilova and Kiselev, 1965;Beger and Schay, 1965; Komers and Kocliloefl, 1967; Beljakova et al, 1967;Figueras et ah, 1967;Fink and 'Walle.schensky, 1968; Padberg and Smith, 1968;Schanel ct al., 1968;Beljakova et al, 1968;Mercea et al, 1968;Ivanova and Zhukhovitskii, 1969;Schanel et al, 1969) for the determination of the adsorption isotherms and isobars of gases and vapors on solid supports and catalysts.…”