Please use this identifier to cite or link to this item:
|Title:||In-situ generation of maximum trivalent cobalt in synthesis of hydrotalcite-like compounds Mg(x)Co(II)(1-x-y)Co(III)(y)(OH)2(NO3)(y)·nH2O|
|Authors:||Xu, Z.P. |
|Citation:||Xu, Z.P., Zeng, H.C. (2000). In-situ generation of maximum trivalent cobalt in synthesis of hydrotalcite-like compounds Mg(x)Co(II)(1-x-y)Co(III)(y)(OH)2(NO3)(y)·nH2O. Chemistry of Materials 12 (9) : 2597-2603. ScholarBank@NUS Repository. https://doi.org/10.1021/cm000053f|
|Abstract:||In-situ generation of trivalent cobalt cations has been investigated for the hydrotalcite-like compounds Mg(x)Co(II)(1-x-y)Co(III)(y)(OH)2(NO3)(y)·nH2O at 25-40 °C under oxygen-containing atmospheres. It is noted that with more involvement of Mg2+ in the compounds, less Co2+ cations are needed to maintain the hydrotalcite-like structure. Because of the presence of the Mg2+, more Co2+ can be oxidized under the current experimental conditions and the highest mole ratios of Co3+ to total cobalt cations (Co3+:Co) observed in this work is 57%. The mole ratio of Co3+ to total metal cations (Co3+:(Mg+Co)) achieved in this work is 31% after 4 days of oxidation reaction, which is close to its upper charge limit to produce a single-phase hydrotalcite-like structure (33%). Two major thermal events are observed when the compounds are heated. The first one at 113-134 °C is attributed to the removal of interlayer water molecules while the second at 274-333 °C to the dehydroxylation and decomposition of intercalated anions. Higher catalytic activity for nitrous oxide (N2O) decomposition is observed for the Mg-Co oxides with the same cobalt content but lower mole ratios of Co3+: Co in their hydrotalcite-like precursors. The reason for this activity variation has also been addressed.|
|Source Title:||Chemistry of Materials|
|Appears in Collections:||Staff Publications|
Show full item record
Files in This Item:
There are no files associated with this item.
checked on Sep 20, 2018
WEB OF SCIENCETM
checked on Sep 4, 2018
checked on Jul 27, 2018
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.