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Micropore size distribution by argon porosimetry for cesium hydrogen salts of 12-tungstophosphoric acid

✍ Scribed by Takashi Yamada; Ken-ichi Johkan; Toshio Okuhara


Book ID
104431585
Publisher
Elsevier Science
Year
1998
Tongue
English
Weight
170 KB
Volume
26
Category
Article
ISSN
1387-1811

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✦ Synopsis


Micropore size distributions of Cs 2.1 H 0.9 PW 12 O 40 and 0.5 wt% Pt-Cs 2.1 H 0.9 PW 12 O 40 as well as H-ZSM-5, H-Y and AlPO 4 -5 as standard porous materials were analyzed by Ar porosimetry, assuming cylindrical pores consisting of oxide ions. The calculated pore-widths of H-ZSM-5, HY and AlPO 4 -5 were in agreement with the pore-opening sizes determined by XRD. The Ar porosimetry demonstrated that Cs 2.1 H 0.9 PW 12 O 40 and 0.5 wt% Pt-Cs 2.1 H 0.9 PW 12 O 40 possess only ultramicropores having widths of about 0.5 nm. Adsorption of various molecules revealed that the pore widths of these heteropoly compounds were in the range 0.43-0.59 nm, which is consistent with the results of the Ar porosimetry. In conclusion, nearly uniformly sized micropores are formed on both Cs 2.1 H 0.9 PW 12 O 40 and 0.5 wt% Pt-Cs 2.1 H 0.9 PW 12 O 40 .