Improvement of methods for surface area determinations

Analysis of uncertainties in manometric gas-adsorption measurements

“…doi:10.1016/j.jcis.2008.07.001 effective (statistical) means for comparison of apparent pore volumes derived from NPRM with different surface chemistry. We acknowledge that various earlier researchers found differences in monolayer regions of adsorption isotherms when using NPRM with surface chemistry different from that for the investigated microporous materials [15][16][17][18] cited among other publications by Sing and Williams [4]. However, the quantification of such differences (or if these differences are significant or not) was not substantiated due to the unavailability of a "comparison measure," which is CSU in micro-and mesopore volumes.…”

Study on Active Carbon-Supported Two-Component Catalysts for NO Conversion

“…For that reason a correction in the adsorbed amount has been made on the basis of the adsorption in the mesopores to obtain the true micropore volume by the DR equation. This correction has been made according to the Karnaukhov equation (16).…”

Intermolecular Repulsions in Adsorbed Layers

“…However, this estimate was based on the assumption of the densest packing of molecules which gave a significantly smaller area per molecule than that in the real monolayer. So the value of 0.138 nm 2 can be reached only for high ε s , for low ε s , the area per molecule is about 0.176 nm 2 (29). Note that the compressed pairs of molecules shown in Figs.…”

“…In the full monolayer of argon molecules, standard surface area per molecule, s, is 0.176 nm 2 (29). However, at very high energies of adsorption, s = s * ≈ 0.138 nm 2 (25,29).…”

“…3, at r = r * ≈ 3.4Å, the potential function is positive, and the two molecules repel each other. A change in the distance between molecules in the adsorbed layer also is known for nitrogen and krypton: surface area per molecule in the monolayer goes down as the BET constant (i.e., the energy of the adsorbate-adsorbent interaction, ε s ) goes up (29).…”