Preparation of double pyrophosphates in aqueous systems chromium(III) salt−sodium pyrophosphate
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- 作者：S. V. Chuppina ; V. A. Zhabrev ; M. V. Larina
- 刊名：Russian Journal of Inorganic Chemistry
- 出版年：2016
- 出版时间：November 2016
- 年：2016
- 卷：61
- 期：11
- 页码：1361-1367
- 全文大小：770 KB
- 刊物类别：Chemistry and Materials Science
- 刊物主题：Chemistry
Inorganic Chemistry
Russian Library of Science - 出版者：MAIK Nauka/Interperiodica distributed exclusively by Springer Science+Business Media LLC.
- ISSN：1531-8613
- 卷排序：61
文摘
The specifics of preparation of chromium double pyrophosphates in systems Cr(NO3)3–Na4P2O7–H2O, CrCl3–Na4P2O7–C2O, and KCr(SO4)2–Na4P2O7–H2O are discussed. Changes in pH of the mentioned systems have been studied depending of the component ratio. The effects of the deposition duration and sodium pyrophosphate concentration on pH have been studied for system Cr(NO3)3–Na4P2O7–H2O. Phase composition has been determined for compounds prepared in systems Cr(NO3)3–Na4P2O7–H2O and KCr(SO4)2–Na4P2O7–H2O. It has been found that the acid residue anions do not substantially affect the formation of a continuous series of compounds consisting of hydroxy and hydro combinations of chromium ions and pyrophosphate ion, whereas cations can have an effect. System KCr(SO4)2–Na4P2O7–C2O is less sensitive to reaction conditions than systems in which normal salts Cr(NO3)3 and CrCl3 act as a source of Cr3+ cation. A product stable over time can be prepared in system KCr(SO4)2–Na4P2O7–C2O; after heat treatment at 900°C, it is a mixture of KCrP2O7 and a-CrPO4 phases.