Mv. Sychev et al., STUDY OF POROUS STRUCTURE OF PILLARED CLAYS - 1 - MONTMORILLONITE FIXED BY CHROMIUM(III) OXIDE, Kinetics and catalysis, 39(1), 1998, pp. 106-113
The porous structure of montmorillonite fixed by chromium oxide was st
udied by nitrogen, water vapor, and benzene adsorption. The adsorption
data obtained were analyzed in detail by the alpha(s)-method and the
theory of volume filling of micropores. The fixation of acid-treated m
ontmorillonite K10 by hydroxochromium cations resulted in the formatio
n of the pillared clay with considerable mesoporosity. Additional micr
opores appeared, and new polar adsorption sites were formed. The role
of new absorption sites belongs to hydroxochromium cations or chromium
oxide clusters localized in the interlayer space of the pillared clay
. A microporous material was found to be formed mostly by the fixation
of Oglanli bentonite. The calcination of the synthesized pillared cla
ys at 673 K resulted in an increase in the average width of their micr
opores and mesoporosity. The porous montmorillonite structure fixed by
chromium oxide can be purposefully formed using clays of different ch
emical composition and physical and chemical properties.