Kim Kwang-Wook, Kim Young-Jun, Kim In-Tae, Park Gun-Ii, Lee Eil-Hee
Korea Atomic Energy Research Institute, 150 Dukjin, Yusong, Daejeon, 305-600, Korea.
Water Res. 2006 Apr;40(7):1431-41. doi: 10.1016/j.watres.2006.01.042. Epub 2006 Mar 20.
In order to evaluate the electrolytic decomposition characteristics of ammonia to nitrogen, this work has studied several experimental variables of electrolytic ammonia decomposition. The effects of the pH and the chloride ion in the solution, kinds of anodes such as IrO(2,) RuO(2), and Pt on the electrolytic decomposition of ammonia were compared, and the existence of a membrane equipped in the cell, the changes of the current density, the initial ammonia concentration, and so on were investigated for the decomposition. The performances of the electrode were totally in the order of RuO(2) approximately IrO(2) > Pt in both the acid and alkali conditions. The ammonia decomposition was the highest at a current density of 80 mA/cm(2), over which it decreased, because the adsorption of the ammonia at the electrode surface was hindered by the hydroxyl ions in the solution. The ammonia decomposition yield increased with the concentration of the chloride ion in the solution. However, the increment rate became much lesser over 10 g/l of the chloride ion. The RuO(2) electrode among the tested anodes generated the most OH radicals which could oxidize the ammonium ion at pH 7.
为了评估氨电解分解为氮的特性，本工作研究了氨电解分解的几个实验变量。比较了溶液中的pH值和氯离子、IrO₂、RuO₂和Pt等阳极种类对氨电解分解的影响，并研究了电池中配备膜的情况、电流密度、初始氨浓度等变化对分解的影响。在酸性和碱性条件下，电极性能总体上顺序为RuO₂≈IrO₂＞Pt。在电流密度为80 mA/cm²时氨分解率最高，超过该值后分解率下降，这是因为溶液中的氢氧根离子阻碍了氨在电极表面的吸附。氨分解产率随溶液中氯离子浓度的增加而增加。然而，当氯离子浓度超过10 g/l时，增加速率变得小得多。在所测试的阳极中，RuO₂电极产生的羟基自由基最多，这些自由基在pH值为7时可氧化铵离子。
