Electron Attachment and Compound Formation in Flames. III. Negative Ion and Compound Formation in Flames Containing Tungsten and Potassium
Electron Attachment and Compound Formation in Flames. III. Negative Ion and Compound Formation in Flames Containing Tungsten and Potassium
复制标题
火焰中的电子附着和化合物形成。
DOI：
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发表时间：
1970
期刊：
影响因子：
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通讯作者：
W. Miller
中科院分区：
文献类型：
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作者：
D. Jensen;W. Miller
几种不同的实验技术（火焰离子质谱，微波腔共振，静电探针，和吸收分光光度法）的应用表明，除了钨富燃料的大气压H2/O2/N2火焰与钾种子的结果在减少游离钾原子的浓度和形成稳定的含W的负离子。下面的反应图式和焓变提供了对实验结果满意的定量解释：K+ H2 WO 4 <$KHWO4 +H; Δ H 0 ° = − 40 ± 40 kJ mol−1，H2 WO 4 +e− <$HWO4 −+H; Δ H 0 ° = + 40 ± 40 kJ mol−1，HWO 4 −+H <$WO3 −+H2O; Δ H 0 ° = − 22 ± 40 kJ mol−1。焓变意味着WO 3和HWO 4的电子亲和力分别约为351和420 kJ mol−1。
Application of several different experimental techniques (flame-ion mass spectrometry, microwave cavity resonance, electrostatic probe, and absorption spectrophotometry) reveals that addition of tungsten to fuel-rich atmospheric-pressure H2/O2/N2 flames seeded with potassium results in reductions in concentrations of free potassium atoms and in formation of stable W-containing negative ions. The following reaction scheme and enthalpy changes provide a satisfactory quantitative interpretation of the experimental results: K+H2WO4⇆KHWO4+H; ΔH0° = − 40 ± 40 kJ mol−1, H2WO4+e−⇆HWO4−+H; ΔH0° = + 40 ± 40 kJ mol−1, HWO4−+H⇆WO3−+H2O; ΔH0° = − 22 ± 40 kJ mol−1. The enthalpy changes imply electron affinities for WO3 and HWO4 of approximately 351 and 420 kJ mol−1, respectively.