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The Reaction of Oxides with Water at High Pressures and Temperatures
Author(s) -
Wendlandt H. G.,
Glemser O.
Publication year - 1964
Publication title -
angewandte chemie international edition in english
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 0570-0833
DOI - 10.1002/anie.196400471
Subject(s) - supercritical fluid , chemistry , phase (matter) , gas phase , liquid phase , water vapor , inorganic chemistry , analytical chemistry (journal) , organic chemistry , thermodynamics , physics
The reactions of the oxides SiO 2 , MoO 3 , and WO 3 with steam at temperatures between 400 and 700 °C and pressures of 5 to 500 atm were studied by means of the transfer method. The results were evaluated by a new method. In the system Sio 2 /H 2 O the formation of gaseous Si(OH) 4 , Si 2 O(OH) 6 , and [SiO 2 (OH) 2 ] x was found to occur in three different water‐density ranges. In the systems MoO 3 /H 2 O and WO 3 /H 2 O the gaseous compounds MoO 2 (OH) 2 and WO 2 (OH) 2 , which were already known, exist up to densities of approximately 0.05g/cm 3 . At higher densities, at which the supercritical phase begins to show the properties of a liquid to an ever increasing extent, isopolymolybdic or isopolytungstic acids appear.