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Kinetics of Anatase TiO 2 Surface Area Reduction in a Mixture of HCI, H 2 O, and O 2 : II, Quantitative Modeling
Author(s) -
Gruy Frédéric,
Pijolat Michèle
Publication year - 1992
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.1992.tb07856.x
Subject(s) - anatase , partial pressure , chlorine , chemistry , kinetics , diffusion , ion , oxide , chloride , vapour pressure of water , inorganic chemistry , water vapor , phase (matter) , chemical engineering , thermodynamics , oxygen , catalysis , organic chemistry , physics , photocatalysis , quantum mechanics , engineering
From the experimental rate for surface area reduction of anatase TiO 2 , expressed versus the partial pressure in H 2 O and the surface content of chloride ion, a kinetic model is proposed in which two parallel mechanisms are involved. Two ways of material transport appear to contribute to the surface area loss: in the vapor phase and at the surface of the oxide. The related rate‐determining steps are attributed to the formation of the volatile compound Ti(OH) 2 Cl 2 in the first case, and to the diffusion of hydroxyl ions in the second one. At high partial pressure of water, the rate is enhanced by surface interactions between water molecules and chlorine‐containing species.