Quotation and calculation accuracy can play a key role in a scientific paper. This comment mainly presents the possible errors in an article by Akqay et al., including the questionable expression of Polanyi potential (epsilon) in the Dubinin-Radushkevich (DR) equation used by the authors and the discrepancies in adsorption thermodynamic parameters study. (C) 2007 Elsevier B.V. All rights reserved.