Effects of Crystallographic Structures of Metal-Phthalocyanine on Electrocatalytic Properties of Oxygen Reduction in Acidic Condition
Effects of Crystallographic Structures of Metal-Phthalocyanine on Electrocatalytic Properties of Oxygen Reduction in Acidic Condition
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DOI：
10.1007/s12678-019-00553-2
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发表时间：
2019-11
期刊：
影响因子：
3.1
通讯作者：
Satoko Takase;Y. Aoto;Daiki Ikeda;H. Wakita;Y. Shimizu
中科院分区：
文献类型：
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作者：
Satoko Takase;Y. Aoto;Daiki Ikeda;H. Wakita;Y. Shimizu
在酸性条件下，研究了金属酞菁（金属：Co，Ni，Cu，Zn）α-β晶相的晶体结构对电化学氧还原催化活性的影响。由于α相和β相结构中中心金属的距离分别为3.8 μ m和4.8 μ m，它们接近于氧分子的大小（3.6 μ m）。采用界面沉积法制备了金属酞菁配合物相。用X射线衍射和X射线光电子能谱对催化剂粉末进行了表征。电化学氧还原性能主要通过使用负载有金属酞菁的气体扩散型碳电极来测量。结果表明，钴和铜中心酞菁的催化活性随着β相向α相的转化而增强。在金属酞菁的晶体结构中的金属之间的距离的影响，应该解释的吸附氧状态，取决于金属之间的距离。α相具有允许形成氧分子的桥构型的距离，所述氧分子的桥构型需要两个吸附位点并且最终通过直接4电子途径产生H2O。用旋转圆盘电极系统分析表明，α-相金属酞菁增强了4-电子还原途径。
Effects of the crystallographic structures of metal-phthalocyanines (metal: Co, Ni, Cu, Zn) between α and β phases on electrochemical oxygen reduction catalytic activities were investigated in acidic condition. As the distances of centered-metal in the structures of α and β phases are 3.8 Å and 4.8 Å, respectively, they were closed to the size of an oxygen molecule (3.6 Å). The phases of metal-phthalocyanines were conducted by an interface deposition method. The obtained catalyst powders were characterized by means of X-ray diffraction and X-ray photoelectron spectra analyses. Electrochemical oxygen reduction performances were mainly measured by using a gas diffusion type carbon electrode loaded with a metal-phthalocyanine. It was confirmed that the catalytic activities of cobalt- and copper-centered phthalocyanines were enhanced by the conversion from β to α phases. The effects of the distance between the metals in the crystallographic structures of metal-phthalocyanines should be explained by the adsorbed oxygen states that depend on the distance between the metals. The α phase has the distance which allows to form the bridge configuration of oxygen molecule which requires two adsorption sites and that eventually produces H2O by the direct 4-electron pathway. Analysis with the rotating disk electrode system showed that the α-phased metal-phthalocyanines enhance the 4-electron reduction pathway.Graphical abstract.