Open AccessAdsorption of Carbon Dioxide on Mesoporous Silicas near the Critical Temperature
Author(s) -
Narihito Tatsuda,
Yasutomo Goto,
Norihiko Setoyama,
Yoshiaki Fukushima
Publication year - 2005
Publication title -
adsorption science and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.682
H-Index - 36
eISSN - 2048-4038
pISSN - 0263-6174
DOI - 10.1260/026361705776316569
Subject(s) - mesoporous material , adsorption , capillary condensation , chemistry , carbon dioxide , condensation , chemical engineering , thermodynamics , organic chemistry , catalysis , physics , engineering
The adsorption of carbon dioxide on mesoporous silicas was studied near the critical temperature (T c ) of CO 2 , i.e. 304.2 K. The critical temperature in the mesopores at which the first-order phase transition (capillary condensation) was observed (T cp ) was estimated from the inverse slope of the adsorption isotherms and the behaviour of the adsorption isotherms per unit surface area. The values of T cp for CO 2 in mesopores whose radii, r p , were 3.02 and 2.14 nm were higher than those estimated using a slab model in which the adsorbing parts of layer were clearly separated from the non-adsorbing regions. The differential heat of adsorption decreased with increasing pore size of the mesoporous adsorbent. This result also suggested a deviation from the slab model.