Complex formation during dissolution of metal oxides in molten alkali carbonates

Qingfeng Li, Flemming Borup, Irina Petrushina, Niels Bjerrum

    Research output: Contribution to journalJournal articleResearchpeer-review

    755 Downloads (Pure)

    Abstract

    Dissolution of metal oxides in molten carbonates relates directly to the stability of materials for electrodes and construction of molten carbonate fuel cells. In the present work the solubilities of PbO, NiO, Fe2O3,and Bi2O3 in molten Li/K carbonates have been measured at 650 degrees C under carbon dioxide atmosphere. It is found that the solubilities of NiO and PbO decrease while those of Fe2O3 and Bi2O3 remain approximately constant as the lithium mole fraction increases from 0.43 to 0.62 in the melt. At a fixed composition of the melt, NiO and PbO display both acidic and basic dissolution as the partial pressure of carbon dioxide varies. By combination of solubility and electromotive force measurements, a model is constructed assuming the dissolution involves complex formation. The possible species for lead are proposed to be [Pb(CO3)(2)](-2) and/or [Pb(CO3)(3)](-4). A similar complex chemistry for nickel oxide dissolution might be expected. (C) 1999 The Electrochemical Society. S0013-4651(98)11-017-0. All rights reserved.
    Original languageEnglish
    JournalJournal of The Electrochemical Society
    Volume146
    Issue number7
    Pages (from-to)2449-2454
    ISSN0013-4651
    DOIs
    Publication statusPublished - 1999

    Bibliographical note

    Copyright The Electrochemical Society, Inc. [1999]. All rights reserved. Except as provided under U.S. copyright law, this work may not be reproduced, resold, distributed, or modified without the express permission of The Electrochemical Society (ECS).

    Fingerprint Dive into the research topics of 'Complex formation during dissolution of metal oxides in molten alkali carbonates'. Together they form a unique fingerprint.

    Cite this