Details

Autor(en) / Beteiligte

• Pomonis, P.J.
• Petrakis, D.E.
• Ladavos, A.K.
• Kolonia, K.M.
• Pantazis, C.C.
• Giannakas, A.E.
• Leontiou, A.A.

Titel

The I-point method for estimating the surface area of solid catalysts and the variation of C-term of the BET equation

Ist Teil von

• Catalysis communications, 2005, Vol.6 (1), p.93-96

Ort / Verlag

Elsevier B.V

Erscheinungsjahr

2005

Quelle

Access via ScienceDirect (Elsevier)

Beschreibungen/Notizen

• The BET equation rearranged in the form [ V(1 − P)]/ P = CV m − ( C − 1)[ V(1 − P)] was used for the calculation of specific surface areas of porous catalysts and the variation of C-term during the progress of adsorption. This novel method employs plots of [ V(1 − P)]/ P vs. [ V(1 − P)] which provide inclined- V type lines with an inversion point termed I-point. This I-point corresponds exactly to V(1 − P) = V m, i.e., the volume of nitrogen necessary for the formation of a monolayer. The slope of the plots corresponds to ( C − 1) from which the values of C can be estimated in the whole range 0 < P < 1. As the I-point is approached, the C values approach the C BET values calculated from the classical linear BET plots. The free energy of adsorption in the whole range 0 < P < 1 can be also estimated from the relationship RT ln C.