Showing papers on "BET theory published in 1976"
TL;DR: The theoretical background to the BET theory is outlined and a critical examination made of the two parameters calculated from this theory -the BET C constant and the monolayer capacity as mentioned in this paper.
140 citations
TL;DR: In this paper, a destructive action of doped Cu(II) ions on the crystal formation was recognized and discussed based on the crystallographic structure of γ-FeOOH.
39 citations
01 May 1976
TL;DR: In this article, the surface properties of synthetic hydroxyapatite have been investigated by following the changes in enthalpy of immersion (in water, 2-propanol and hexane) as the hydroxyAPatite is degassed at temperatures up to 773°K Concurrent measurements of weight loss, surface area and amount of active hydrogen on the surface were also made.
Abstract: The surface properties of synthetic hydroxyapatite have been investigated by following the changes in enthalpy of immersion (in water, 2-propanol and hexane) as the hydroxyapatite is degassed at temperatures up to 773°K Concurrent measurements of weight loss, BET surface area and amount of “active” hydrogen on the surface were also made By comparing total weight loss with the amount of active hydrogen on the surface an attempt has been made to distinguish between internal and surface hydration The effect of each type of hydration on surface properties is discussed Up to 373°K, a considerably amount of water, probably both internal and surface, is lost Between 373 and 573°K, the weight loss and changes in surface properties appears to be almost entirely associated with the loss of surface water Above 573°K the loss of internal structural water or OH also affects the surface properties
18 citations
Patent•
BP1
TL;DR: In this article, a graphite containing carbon having a basal plane surface area of at least 100 m 2 /g, a ratio of the edge surface area to the base surface area, not more than 5:1, and active component, 0.01 to 10% by weight, of the total weight of catalyst of a platinum group metal disposed thereon.
Abstract: Hydrogen transfer catalyst comprises (a) as support a graphite containing carbon having (1) a basal plane surface area of at least 100 m 2 /g, (2) a ratio of BET surface area to basal plane surface area of not more than 5:1 and (3) a ratio of basal plane surface area to edge surface area of at least 5:1 and (b) as active component, 0.01 to 10% by weight, of the total weight of catalyst of a platinum group metal disposed thereon. The catalyst is particularly suitable for reforming.
15 citations
Patent•
02 Jun 1976TL;DR: In this paper, the aluminum oxide catalyst is an active or activated hydrated aluminum oxide having a particle size between 0.5 and 20 mm, a BET surface area of at least 200 m2 /g, a porosity equal to or greater than 1.5 mm/g, and an X-ray spectrum which shows the reflections of γ-alumina wherein the content of microcrystalline constituents is less than 50 percent by weight.
Abstract: Thymol can be prepared on a continuous basis by reacting m-cresol with propylene and/or compounds which eliminate propylene, over aluminum oxide catalysts in the presence of a nitrogen base. The aluminum oxide catalyst is an active or activated hydrated aluminum oxide having a particle size between 0.5 and 20 mm, a BET surface area of at least 200 m2 /g, a porosity equal to or greater than 0.5 mm/g, a boehmite content of 5 to 40 percent by weight, and an X-ray spectrum which shows the reflections of γ-alumina wherein the content of microcrystalline constituents is less than 50 percent by weight.
4 citations
15 Aug 1976
TL;DR: In this article, rates and collision efficiencies for ozone decomposition on aluminum oxide surfaces were determined and an activation energy of 7.2 kcal/mole was found for the heterogeneous reaction between -40 C and 40 C.
Abstract: Rates and collision efficiencies for ozone decomposition on aluminum oxide surfaces were determined. Samples were characterized by BET surface area, X-ray diffraction, particle size, and chemical analysis. Collision efficiencies were found to be between 2 times 10 to the -10 power and 2 times 10 to the -9 power. This is many orders of magnitude below the value of 0.000001 to 0.00001 needed for appreciable long-term ozone loss in the stratosphere. An activation energy of 7.2 kcal/mole was found for the heterogeneous reaction between -40 C and 40 C. Effects of pore diffusion, outgassing and treatment of the aluminum oxide with several chemical species were also investigated.
3 citations