Synthesis of birnessites using alcohols as reducing reagents: Effects of synthesis parameters on the formation of birnessites

Journal Article · Sun Aug 01 04:00:00 EDT 1999 · Chemistry of Materials

DOI:https://doi.org/10.1021/cm980399e· OSTI ID:696616

Ma, Y; Luo, J; Suib, S L ^[1]

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1. Univ. of Connecticut, Storrs, CT (United States)

This study shows that synthetic birnessite, an octahedral layered manganese oxide material called OL-1 can be synthesized with Na{sup +}, K{sup +}, Na{sup +}/Mg{sup 2+}, or K{sup +}/Mg{sup 2+} ions as interlayer cations by redox reactions between permanganate and alcohols in a strong basic media. The synthesis processes were followed by powder X-ray diffraction (XRD) studies. OL-1 samples have been characterized by XRD, chemical analysis, average oxidation states measurements, and scanning electron microscopy studies. Results show that all OL-1 samples have an interlayer spacing of {approximately} 7.0 {angstrom}. The average oxidation states of manganese fall in a range of 3.60--3.70. The chemical compositions for typical Na-OL-1 and K-OL-1 are Na{sub 4.7}Mn{sub 14}O{sub 27.7} {center_dot} 8.7H{sub 2}O and K{sub 4.6}Mn{sub 14}O{sub 27.9} {center_dot} 6.6H{sub 2}O, respectively. {alpha}-MnO(OH) coexists with Na-OL-1 in the synthesis where NaMnO{sub 4} aqueous solution is added to the solution containing ethanol, water, and sodium hydroxide. When Mg(MnO{sub 4}){sub 2} was used as the oxidant, more Mg{sup 2+} ions were accommodated in OL-1 than in previous reports. The interlayer space is propped opened by intercalating hexylammonium ions between the layers, confirming the layered structure.

• Sponsoring Organization: USDOE, Washington, DC (United States)
• OSTI ID: 696616
• Journal Information: Chemistry of Materials, Journal Name: Chemistry of Materials Journal Issue: 8 Vol. 11; ISSN CMATEX; ISSN 0897-4756
• Country of Publication: United States
• Language: English

Related Subjects

40 CHEMISTRY
AIR POLLUTION CONTROL
CATALYSTS
CATHODES
CHEMICAL PREPARATION
ENVIRONMENTAL TRANSPORT
GROUND WATER
HYDROGENATION
MANGANESE OXIDES
RADIOACTIVE WASTE PROCESSING