Showing papers on "BET theory published in 1981"
TL;DR: In this article, the effect of surface acidic groups of activated carbons on their adsorption characteristics for substrates from aqueous solutions was studied. And the substitution of benzoic acid by phenol scarcely proceeds.
50 citations
TL;DR: In this article, the catalytic behavior of SnO2P2O5 catalysts is compared with that of crystalline tin(IV) phosphate, and the interdependence of catalytic activity and selectivity, catalyst crystalline structure, and BET surface area is also discussed.
47 citations
TL;DR: Silica-intercalated hectorite with an 001 spacing of 12.6/~ and a Nz BET surface area of 220 mZ/ g was prepared by hydrolysis and oxidation at 500~ of hectorsite containing a silicon acetylacetonate com- plex as discussed by the authors.
Abstract: Silica-intercalated hectorite with an 001 spacing of 12.6/~ and a Nz BET surface area of 220 mZ/ g was prepared by hydrolysis and oxidation at 500~ of hectorite containing a silicon acetylacetonate com- plex. The intercalate swelled to higher spacings upon adsorption of water, glycerol, and pyridine, but the silica was not expelled when the interlayers swelled and contracted in successive adsorption/desorption cycles. The surface area measured by isobutane adsorption agrees with the N~ BET surface area, suggesting that the interlayers are available for adsorption of aliphatic hydrocarbons. The intercalated silica did not inhibit the ability of the interlayers to enter into cation-exchange reactions, as judged from Cu2+-binding experiments. Infrared studies of NH3-, pyridine-, and NO2-adsorption indicate the presence of Bronsted acidity and the absence of Lewis acidity in the interlayer regions.
28 citations
Patent•
07 Dec 1981
TL;DR: In this paper, the authors proposed a mixture of oxides of molybdenum, cobalt, iron, bismuth, thallium, antimony, silicon, and nickel, along with one or more members of the groups consisting of the alkali metals, the alkaline earth metals, rare earth metals including lanthanum, tungsten, and mixtures thereof.
Abstract: A catalyst composition useful for the oxidation of olefins, particularly the vapor phase oxidation of isobutylene and/or tertiary butyl alcohol to produce methacrolein, consists essentially of the combination of oxides of molybdenum, cobalt, iron, bismuth, thallium, antimony, silicon, and nickel, along with one or more members of the groups consisting of the alkali metals, the alkaline earth metals, the rare earth metals including lanthanum, tungsten, and mixtures thereof. The catalyst has a BET surface area within the range of about 0.5-10 m 2 /gm and preferably within the range of about 2-6 m 2 /gm. Preferably, the catalyst has no more than about 3% of the surface area associated with pores smaller than about 100 A°. The catalyst is heated during its preparation to a temperature above 525° C., preferably above 550° C., most preferably to about 600° C., for a time sufficient to achieve the desired surface area and pore size distribution and thereby to improve selectivity to methacrolein.
23 citations
TL;DR: In this paper, the adsorption of CO and CO2 on chromia-promoted magnetite was studied volumetrically at temperatures near 650 K using CO 2 CO gas mixtures in which magnetite is the thermodynamically stable form of iron oxide.
17 citations
TL;DR: In this article, the performance of octane adsorption on cellophane at 20°C and at several relative humidities (¯RH) was studied by elution gas chromatography.
12 citations
TL;DR: In this paper, the saturation adsorption of the chalcopyrite samples is proportional to their surface area, with 2.18 ± 0.07 μ mol of dye being adsorbed per m 2 of surface.
10 citations
TL;DR: In this paper, the nitrogen Brunauer-Emmett-Teller (BET) surface areas and the heat of immersion in water are estimated and discussed and all these changes are dependent on the pretreatment temperature.
6 citations
3 citations
TL;DR: In this paper, surface areas were measured on UO 2 kernels of different porosities by the adsorption of krypton; this was carried out in a special apparatus at a temperature of 77 K. The V l - t plot was a straight line for porous solids in the low pressure region.
2 citations