TY - JOUR
T1 - Water Oxidation by λ-MnO2
T2 - Catalysis by the Cubical Mn4O4 Subcluster Obtained by Delithiation of Spinel LiMn2O4
AU - Robinson, David M.
AU - Go, Yong Bok
AU - Greenblatt, Martha
AU - Dismukes, G. Charles
PY - 2010/8/25
Y1 - 2010/8/25
N2 - Nanocrystalline spinel LiMn2O4 has been prepared and treatment of LiMn2O4 with dilute nitric acid solution resulted in the delithiation of the framework, while maintaining the spinel structure, λ-MnO2. LiMn2O4 is not a catalyst for water oxidation. Upon removal of the lithium, the cubical Mn 4O4 cores become active sites for oxidizing water to molecular oxygen, which was investigated with the photochemical [Ru 2+(2,2′-bpy)3]/persulfate system at pH 5.8. The nanosize λ-MnO2 obtained from the nanocrystalline LiMn 2O4, which was synthesized by the citrate route, shows a significantly higher water oxidation catalytic activity (Turnover Frequency: 3 × 10-5 mol O2/s/mol Mn) than that obtained via solid state reaction with micrometer and irregular particle sizes (Turnover Frequency: 5 × 10-6 mol O2/s/mol Mn).
AB - Nanocrystalline spinel LiMn2O4 has been prepared and treatment of LiMn2O4 with dilute nitric acid solution resulted in the delithiation of the framework, while maintaining the spinel structure, λ-MnO2. LiMn2O4 is not a catalyst for water oxidation. Upon removal of the lithium, the cubical Mn 4O4 cores become active sites for oxidizing water to molecular oxygen, which was investigated with the photochemical [Ru 2+(2,2′-bpy)3]/persulfate system at pH 5.8. The nanosize λ-MnO2 obtained from the nanocrystalline LiMn 2O4, which was synthesized by the citrate route, shows a significantly higher water oxidation catalytic activity (Turnover Frequency: 3 × 10-5 mol O2/s/mol Mn) than that obtained via solid state reaction with micrometer and irregular particle sizes (Turnover Frequency: 5 × 10-6 mol O2/s/mol Mn).
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U2 - 10.1021/ja1055615
DO - 10.1021/ja1055615
M3 - Article
C2 - 20672802
AN - SCOPUS:77955832666
VL - 132
SP - 11467
EP - 11469
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
SN - 0002-7863
IS - 33
ER -