Reaction of lanthanum bromide oxide with water vapour

Jutang Sun; Takashi Kyotani; Yasukatsu Tamai; Akira Tomita

doi:10.1016/0168-7336(85)80004-8

Reaction of lanthanum bromide oxide with water vapour

Jutang Sun, Takashi Kyotani, Yasukatsu Tamai, Akira Tomita

Research output: Contribution to journal › Article › peer-review

Abstract

The reaction of lanthanum bromide oxide (LaOBr) with water vapour was investigated by thermogravimetric analysis in the temperature range 323-358 K and in the relative humidity range 80-98%. The influences of temperature, water partial vapour pressure and relative humidity on the reaction were studied. A Fourier transform infrared spectrometer and an X-ray diffractometer were used to determine the reaction intermediates and products. Microscopic observations of the samples were made with a scanning electron microscope as the reaction proceeded. Lanthanum bromide hydroxide monohydrate [LaBr(OH)₂ · H₂O] was identified as a final product. The reaction is an auto-catalytic one. A model of the reaction mechanism is proposed, consisting of several steps: (a) adsorption of water vapour and the formation of a water film, (b) formation of La(OH)⁺₂ and Br^- ions in the water film and (c) nucleation and crystal growth of LaBr(OH)₂ · H₂O. The proposed model explains the various features of reaction very well.

Original language	English
Pages (from-to)	19-30
Number of pages	12
Journal	Reactivity of Solids
Volume	1
Issue number	1
DOIs	https://doi.org/10.1016/0168-7336(85)80004-8
Publication status	Published - 1985 Jan 1

ASJC Scopus subject areas

Engineering(all)

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10.1016/0168-7336(85)80004-8

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title = "Reaction of lanthanum bromide oxide with water vapour",

abstract = "The reaction of lanthanum bromide oxide (LaOBr) with water vapour was investigated by thermogravimetric analysis in the temperature range 323-358 K and in the relative humidity range 80-98%. The influences of temperature, water partial vapour pressure and relative humidity on the reaction were studied. A Fourier transform infrared spectrometer and an X-ray diffractometer were used to determine the reaction intermediates and products. Microscopic observations of the samples were made with a scanning electron microscope as the reaction proceeded. Lanthanum bromide hydroxide monohydrate [LaBr(OH)2 · H2O] was identified as a final product. The reaction is an auto-catalytic one. A model of the reaction mechanism is proposed, consisting of several steps: (a) adsorption of water vapour and the formation of a water film, (b) formation of La(OH)+2 and Br- ions in the water film and (c) nucleation and crystal growth of LaBr(OH)2 · H2O. The proposed model explains the various features of reaction very well.",

author = "Jutang Sun and Takashi Kyotani and Yasukatsu Tamai and Akira Tomita",

year = "1985",

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T1 - Reaction of lanthanum bromide oxide with water vapour

AU - Sun, Jutang

AU - Kyotani, Takashi

AU - Tamai, Yasukatsu

AU - Tomita, Akira

PY - 1985/1/1

Y1 - 1985/1/1

N2 - The reaction of lanthanum bromide oxide (LaOBr) with water vapour was investigated by thermogravimetric analysis in the temperature range 323-358 K and in the relative humidity range 80-98%. The influences of temperature, water partial vapour pressure and relative humidity on the reaction were studied. A Fourier transform infrared spectrometer and an X-ray diffractometer were used to determine the reaction intermediates and products. Microscopic observations of the samples were made with a scanning electron microscope as the reaction proceeded. Lanthanum bromide hydroxide monohydrate [LaBr(OH)2 · H2O] was identified as a final product. The reaction is an auto-catalytic one. A model of the reaction mechanism is proposed, consisting of several steps: (a) adsorption of water vapour and the formation of a water film, (b) formation of La(OH)+2 and Br- ions in the water film and (c) nucleation and crystal growth of LaBr(OH)2 · H2O. The proposed model explains the various features of reaction very well.

AB - The reaction of lanthanum bromide oxide (LaOBr) with water vapour was investigated by thermogravimetric analysis in the temperature range 323-358 K and in the relative humidity range 80-98%. The influences of temperature, water partial vapour pressure and relative humidity on the reaction were studied. A Fourier transform infrared spectrometer and an X-ray diffractometer were used to determine the reaction intermediates and products. Microscopic observations of the samples were made with a scanning electron microscope as the reaction proceeded. Lanthanum bromide hydroxide monohydrate [LaBr(OH)2 · H2O] was identified as a final product. The reaction is an auto-catalytic one. A model of the reaction mechanism is proposed, consisting of several steps: (a) adsorption of water vapour and the formation of a water film, (b) formation of La(OH)+2 and Br- ions in the water film and (c) nucleation and crystal growth of LaBr(OH)2 · H2O. The proposed model explains the various features of reaction very well.

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JF - Solid State Ionics

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Reaction of lanthanum bromide oxide with water vapour

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