Study of the hydrothermal synthesis of gallium phosphates using in situ time-resolved X-ray diffraction
The hydrothermal crystallisation (130-180 °C) of three-dimensional open-framework gallium and aluminium oxyfluoro-phosphates with the ULM-3 and ULM-4 structures have been studied in situ for the first time. The in situ energy-dispersive X-ray diffraction method has allowed the formation of the cryst...
Main Authors: | , , , , |
---|---|
Format: | Book section |
Published: |
1999
|
_version_ | 1797069720827985920 |
---|---|
author | Walton, R Loiseau, T Francis, R O'Hare, D Ferey, G |
author_facet | Walton, R Loiseau, T Francis, R O'Hare, D Ferey, G |
author_sort | Walton, R |
collection | OXFORD |
description | The hydrothermal crystallisation (130-180 °C) of three-dimensional open-framework gallium and aluminium oxyfluoro-phosphates with the ULM-3 and ULM-4 structures have been studied in situ for the first time. The in situ energy-dispersive X-ray diffraction method has allowed the formation of the crystalline products to be observed under hydrothermal , conditions The integrated areas of the strongest Bragg reflections has allowed quantitative kinetic data to be extracted. The effect of temperature, phosphorus source, templating agent have been investigated. The nature of phosphorus source in the reaction mixture has been found to affect dramatically the course of reaction for certain combinations of amine and temperature. Previously unobserved transient crystalline phases have been seen during the production of ULM-3 gallium phosphates when ¥265 or polyphosphoric acid are used. The formation of these intermediates affects the kinetics of product growth. In the case of the aluminium ULM-3 materials reaction always proceeds via a crystalline intermediate whatever phosphorus source is used. The ULM-4 framework materials are found to always crystallise directly with no evidence for any intermediates. Kinetic data for each system have been modelled using standard solid-state chemistry expressions, and these calculations indicate the reactions to be diffusion controlled. ©1999 Materials Research Society. |
first_indexed | 2024-03-06T22:28:38Z |
format | Book section |
id | oxford-uuid:5785ba11-f94a-4608-9e23-23b4f15bcd0a |
institution | University of Oxford |
last_indexed | 2024-03-06T22:28:38Z |
publishDate | 1999 |
record_format | dspace |
spelling | oxford-uuid:5785ba11-f94a-4608-9e23-23b4f15bcd0a2022-03-26T16:57:17ZStudy of the hydrothermal synthesis of gallium phosphates using in situ time-resolved X-ray diffractionBook sectionhttp://purl.org/coar/resource_type/c_3248uuid:5785ba11-f94a-4608-9e23-23b4f15bcd0aSymplectic Elements at Oxford1999Walton, RLoiseau, TFrancis, RO'Hare, DFerey, GThe hydrothermal crystallisation (130-180 °C) of three-dimensional open-framework gallium and aluminium oxyfluoro-phosphates with the ULM-3 and ULM-4 structures have been studied in situ for the first time. The in situ energy-dispersive X-ray diffraction method has allowed the formation of the crystalline products to be observed under hydrothermal , conditions The integrated areas of the strongest Bragg reflections has allowed quantitative kinetic data to be extracted. The effect of temperature, phosphorus source, templating agent have been investigated. The nature of phosphorus source in the reaction mixture has been found to affect dramatically the course of reaction for certain combinations of amine and temperature. Previously unobserved transient crystalline phases have been seen during the production of ULM-3 gallium phosphates when ¥265 or polyphosphoric acid are used. The formation of these intermediates affects the kinetics of product growth. In the case of the aluminium ULM-3 materials reaction always proceeds via a crystalline intermediate whatever phosphorus source is used. The ULM-4 framework materials are found to always crystallise directly with no evidence for any intermediates. Kinetic data for each system have been modelled using standard solid-state chemistry expressions, and these calculations indicate the reactions to be diffusion controlled. ©1999 Materials Research Society. |
spellingShingle | Walton, R Loiseau, T Francis, R O'Hare, D Ferey, G Study of the hydrothermal synthesis of gallium phosphates using in situ time-resolved X-ray diffraction |
title | Study of the hydrothermal synthesis of gallium phosphates using in situ time-resolved X-ray diffraction |
title_full | Study of the hydrothermal synthesis of gallium phosphates using in situ time-resolved X-ray diffraction |
title_fullStr | Study of the hydrothermal synthesis of gallium phosphates using in situ time-resolved X-ray diffraction |
title_full_unstemmed | Study of the hydrothermal synthesis of gallium phosphates using in situ time-resolved X-ray diffraction |
title_short | Study of the hydrothermal synthesis of gallium phosphates using in situ time-resolved X-ray diffraction |
title_sort | study of the hydrothermal synthesis of gallium phosphates using in situ time resolved x ray diffraction |
work_keys_str_mv | AT waltonr studyofthehydrothermalsynthesisofgalliumphosphatesusinginsitutimeresolvedxraydiffraction AT loiseaut studyofthehydrothermalsynthesisofgalliumphosphatesusinginsitutimeresolvedxraydiffraction AT francisr studyofthehydrothermalsynthesisofgalliumphosphatesusinginsitutimeresolvedxraydiffraction AT ohared studyofthehydrothermalsynthesisofgalliumphosphatesusinginsitutimeresolvedxraydiffraction AT fereyg studyofthehydrothermalsynthesisofgalliumphosphatesusinginsitutimeresolvedxraydiffraction |