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氨现在认为是不含CO的有效氢气源。本文中,我们已研究了同时有催化的氮分解反应的纳米晶铁的渗氮。化学过程在管状差压流量反应器内,475℃,不同成分的NH3/H2混合气体中进行,也就是不同氮势引入反应器。在每一种氮势下,当固体的质量和氨分解速率恒定时都观察到稳定态。在整个氮势范围内观察到固体的三个不同相分的区域:α铁、α铁和Fe4N化合物的混合物、Fe4N化合物。出现了惊人的现象,随着氮势增加,出现Fe4N化合物相时氨分解下降。为了解释此现象,提出了对过程模型的质疑。和覆盖表面程度有关的氮分解率下降导致氮的偏析唅变化。模型可以确定像氮的体浓度、偏析焓和表面覆盖程度等参数。
Ammonia is now considered an effective hydrogen source without CO. In this paper, we have investigated nitriding of nanocrystalline iron with simultaneous catalytic nitrogen decomposition. The chemical process is carried out in a tubular differential pressure flow reactor at 475 ° C with NH3 / H2 mixtures of different compositions, ie with different nitrogen potential introduced into the reactor. Under each nitrogen potential, a steady state is observed when both the mass of the solid and the ammonia decomposition rate are constant. Three distinct phases of solid were observed throughout the range of nitrogen potential: α-iron, a mixture of α-iron and Fe4N compounds, and Fe4N compounds. An astonishing phenomenon appeared. With the increase of nitrogen potential, ammonia decomposition decreased when Fe4N compound phase appeared. In order to explain this phenomenon, put forward the question of the process model. Decomposition of nitrogen in relation to the degree of coverage of the surface leads to a change in the segregation of nitrogen. The model can determine parameters such as nitrogen concentration, segregation enthalpy and surface coverage.