Anodically deposited manganese oxide and manganese-tungsten oxide electrodes for

2019-06-06 07:33:05

evolution Oxygen tungsten manganese oxide

责任者: Izumiya, K.;Akiyama, E.;Habazaki, H.;Kumagai, N.;Kawashima, A.;Hashimoto, K. 单位: Tohoku Univ, Sendai, Jpn 来源出处: Electrochimica Acta,1998,43(21-22):3303-3312 摘要: The oxygen evolution efficiency in seawater electrolysis has been examined for manganese oxide and manganese-tungsten oxide electrodes anodically deposited on iridium oxide-coated titanium substrates as a function of pH of the deposition electrolytes and tungsten content in the oxides. The oxygen evolution efficiency in 0.5 M NaCl solution at 30°C on the MnO2 electrodes increases with a decrease in pH of the deposition electrolyte. The tungsten-containing electrodes show significantly higher efficiency for oxygen evolution. The tungsten addition enhances oxygen evolution and suppresses chlorine evolution, and hence 99.6% efficiency for oxygen evolution was obtained at 200 A m-2 on the oxide with the molar ratio W6+/(Mn4+ + W6+) of 0.16. The anodically deposited manganese oxide consists of nanocrystalline γ-MnO2. The manganese-tungsten oxides are also composed of a single orthorhombic nanocrystalline γ-MnO2-type phase, in which Mn4+ and W6+ ions are homogeneously distributed, even when cationic fraction of tungsten in the oxide is 0.16. 关键词: Electrochemistry;Electrochemical electrodes;Manganese compounds;Electrodeposition;Electrolysis;Seawater;Oxygen;Electrolytes;Anodes;Surface roughness;pH;Manganese oxide;Manganese tungsten oxide;Anodic deposition;Seawater electrolysis;Oxygen evolution;Tafel slope