Reverse Micelle Assisted Dispersion of Lanthanum Manganite on Carbon Support for Oxygen Reduction Cathode
Reverse Micelle Assisted Dispersion of Lanthanum Manganite on Carbon Support for Oxygen Reduction Cathode
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DOI：
10.1149/1.1633266
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发表时间：
2004
影响因子：
3.9
通讯作者：
H. Masahiko;H. Uemura;K. Shimanoe;N. Miura;N. Yamazoe
中科院分区：
文献类型：
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作者：
H. Masahiko;H. Uemura;K. Shimanoe;N. Miura;N. Yamazoe
以聚氧乙烯-5-壬基苯基醚为表面活性剂，环己烷为溶剂，采用反胶束(RM)法将LaMnO3+δ氧化物分散在炭黑载体上。将一种含有组成金属[Rm(A)]硝酸盐的Rm分散体与另一种含有N(CH3)4OH的分散体混合，制备了一种含有氧化物[Rm(C)]纳米前驱体的Rm分散体。Rm(C)前驱体在空气中或氮气中焙烧后分别转化为六方氧化物(LaMnO3.15)或正交氧化物(LaMnO3.00)，加入乙醇易使其失稳。炭黑粉末在这些制备过程的不同阶段被混合。在所得到的碳载氧化物粉末中，将炭黑悬浮到Rm(A)中的粉末具有出色的阴极活性：在60°C的空气中，在8MKOH中，-80 mV(vs.Hg/HgO)下的电流密度高达300 mA cm-2。透射电子显微镜观察表明，氧化物粒子在碳基质中的细小分散是催化剂活性高的原因。
It was tried to disperse LaMnO 3+δ oxide finely on carbon black support through a reverse micelle (RM) method using poly(oxyethylene) 5 nonylphenyl ether (surfactant), and cyclohexane (solvent). An RM dispersion containing a nanosized precursor of the oxide [RM (C)] was prepared by mixing an RM dispersion containing nitrates of constituent metals [RM (A)] with another dispersion containing N(CH 3 ) 4 OH. RM (C) was easily destabilized with the addition of ethanol to deposit the precursor, which was converted to hexagonal oxide (LaMnO 3.15 ) or orthorhombic oxide (LaMnO 3.00 ) by calcination in air or N 2 , respectively. Carbon black powder was mixed at various stages of these preparation procedures. Among the resulting carbon-supported oxide powders, the one for which the carbon black was suspended into RM (A) was found to give an outstanding cathodic activity: It allowed current density as high as 300 mA cm -2 at -80 mV (vs. Hg/HgO) in 8 M KOH at 60°C under air flow. Transmission electron microscope observation revealed that fine dispersion of the oxide particles in the carbon matrix is the origin of such high activity.