Radical Species Formed by the Catalytic Decomposition of NH3 on Heated W Surfaces
Radical Species Formed by the Catalytic Decomposition of NH3 on Heated W Surfaces
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NH3 在加热的 W 表面上催化分解形成的自由基物质
DOI：
10.1143/jjap.42.5315
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发表时间：
2003
影响因子：
1.5
通讯作者：
H. Matsumura
中科院分区：
文献类型：
--
作者：
H. Umemoto;Kentaro Ohara;Daisuke Morita;T. Morimoto;Moroyuki Yamawaki;A. Masuda;H. Matsumura
用激光光谱技术研究了NH3在加热的W表面上的催化分解过程。H原子和NH2自由基是催化剂表面的主要分解产物。测定了这两个物种的有效生成热容均为150kJ/mol。NH自由基也被确定，但本种的产生归因于次生过程。氮原子是初级和次级过程中的次要产物。绝对密度测量表明，NH3的分解效率与H2相当。用质谱仪测定了NH3及其稳定产物H2和N2的稳态密度。当催化剂温度高于2000K时，H2的密度与残余NH3的密度相当。氢原子不仅由NH3的直接分解产生，也由H2的分解产生。
The catalytic decomposition processes of NH3 on heated W surfaces were examined by employing laser spectroscopic techniques. H atoms and NH2 radicals were identified as primary decomposition products on the catalyzer surfaces. The effective enthalpies for the production of these species were both determined to be 150 kJ/mol. NH radicals were also identified, but the production of this species is ascribed to secondary processes. N atoms are minor products in both the primary and secondary processes. The absolute density measurements show that the decomposition efficiency of NH3 is comparable to that of H2. The steady-state densities of NH3 and the stable products, H2 and N2, were also measured by mass spectrometry. When the catalyzer temperature is over 2000 K, the H2 density is comparable to that of residual NH3. H atoms are produced not only by the direct decomposition of NH3 but also by the decomposition of H2.