THE MECHANISM OF OXYGEN REDUCTION ON IRON IN NEUTRAL SOLUTIONS
THE MECHANISM OF OXYGEN REDUCTION ON IRON IN NEUTRAL SOLUTIONS
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DOI：
10.1149/1.2109021
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发表时间：
1986-09-01
影响因子：
3.9
通讯作者：
BOCKRIS, JO
中科院分区：
文献类型：
--
作者：
JOVANCICEVIC, V;BOCKRIS, JO
研究了铁在中性pH范围内氧还原的途径和速率控制步骤。根据电极表面的性质：裸铁和钝铁，得到了各种机械标准。裸铁上的氧还原通过4E途径进行，只有少量的过氧化氢作为中间产物，并在RDS中形成超氧自由基。在被动铁上，氧还原通过2E途径进行，生成过氧化氢作为反应产物。虽然金属和合金(1-5)在不同pH溶液中的阳极溶解反应已被广泛研究，但在中间pH(6，7)范围内，有关的阴极过程很少受到关注。一般来说，在实际条件下，析氢的阴极反应在酸性溶液中是去极化反应，而氧还原反应在中性和碱性溶液中起到去极化作用。一般认为，中性溶液中的实验工作面临的主要困难是，据称在反应发生时，双电层附近的pH值变化会引起电位变化。
The pathways and rate-determining steps of oxygen reduction on iron in neutral pH range have been investigated. The various mechanistic criteria are obtained as a function of the nature of the electrode surface: bare iron and passive iron. The oxygen reduction on bare iron proceeds through 4e pathways with little hydrogen peroxide as an intermediate and formation of superoxide radical in the rds. On passive iron, oxygen reduction proceeds through a 2e-pathway with the formation of hydrogen peroxide as a reaction product. An rds involving chemisorption of oxygen is suggested.Although the anodic reactions for metal and alloy (1-5) dissolution have been extensively studied in solutions of various pH's, the pertinent cathodic processes have received little attention in the intermediate pH range (6, 7). Generally, under practical conditions, the cathodic reaction of hydrogen evolution is the depolarization reaction in acidic solutions, whereas the oxygen reduction reaction acts as a depolarizer in neutral and alkaline solution. The principal difficulty generally considered to confront experimental work in neutral solutions relates to alleged contributions to the potential change caused by changes in pH in the vicinity of the double layer when the reaction occurs.