Electrochemical generation of hydrogen peroxide from dissolved oxygen in acidic solutions
Electrochemical generation of hydrogen peroxide from dissolved oxygen in acidic solutions
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DOI：
10.1016/s0043-1354(01)00235-4
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发表时间：
2002-01-01
期刊：
影响因子：
12.8
通讯作者：
Huang, CP
中科院分区：
文献类型：
--
作者：
Qiang, ZM;Chang, JH;Huang, CP
过氧化氢（H2O2）是在平行板电解槽中通过在含有稀支撑电解质的酸性溶液中还原溶解氧（DO）而产生的。系统考察了阴极电位、氧纯度和质量流量、阴极表面积、pH、温度和惰性支撑电解质浓度等操作参数，以提高生成H2O2的法拉第电流效率。结果表明，H2O2只有在高pH（> ~ 9）和高温（> ~ 23℃）下才会发生显著的自分解。结果还表明，H2O2生成的最佳条件为阴极电位-0.5 V vs饱和甘汞电极（SCE），氧质量流量8.2 × 10(-2) mol/min, pH 2。在最优条件下，平均电流密度为6.4 A/m(2)，平均电流效率为81%。然而，当空气以最佳氧气流量施加时，平均电流密度显著降低至2.1 A/m(2)，而平均电流效率略有提高至90%。极限电流密度为6.4 A/m(2)，与阴极几何形状和表面积无关。H2O2在低温下生成有利。在所研究的浓度范围内（0.01 ~ 0.25 M），惰性支撑电解质（NaClO4）影响电解槽的总电位降，但不影响H2O2的净生成速率。2001爱思唯尔科学有限公司版权所有。
Hydrogen peroxide (H2O2) was electro-generated in a parallel-plate electrolyzer by reduction of dissolved oxygen (DO) in acidic solutions containing dilute supporting electrolyte. Operational parameters such as cathodic potential, oxygen purity and mass flow rate, cathode surface area, pH, temperature, and inert supporting electrolyte concentration were systematically investigated as to improve the Faradic current efficiency of H2O2 generation. Results indicate that significant self-decomposition of H2O2 only occurs at high pH ( > 9) and elevated temperatures (> 23 degreesC). Results also indicate that the optimal conditions for H2O2 generation are cathodic potential of -0.5 V vs. saturated calomel electrode (SCE), oxygen mass flow rate of 8.2 x 10(-2) mol/min, and pH 2. Under the optimal conditions, the average current density and average current efficiency are 6.4 A/m(2) and 81%, respectively. However, when air is applied at the optimal flow rate of oxygen, the average current density markedly decreases to 2.1 A/m(2), while the average current efficiency slightly increases to 90%. The limiting current density is 6.4 A/m(2), which is independent of cathode geometry and surface area. H2O2 generation is favored at low temperatures. In the concentration range studied (0.01-0.25 M), the inert supporting electrolyte (NaClO4) affects the total potential drop of the electrolyzer, but does not affect the net generation rate of H2O2. (C) 2001 Elsevier Science Ltd. All rights reserved.