煤焦催化HCN还原NO的反应机理

发布时间：2018-06-04 12:10

本文选题：HCN + 煤焦　；参考：《燃料化学学报》2017年09期

【摘要】：通过量子化学密度泛函理论研究了均相和煤焦催化的HCN还原NO反应机理,计算了反应动力学参数。结果表明,均相还原反应的活化能为306 kJ/mol,而煤焦催化的NO还原反应的活化能为136 kJ/mol。典型再燃温度1 400 K下,HCN异相还原NO的反应速率略小于煤焦异相还原NO的反应速率;HCN参与下的煤焦异相还原NO反应较CO参与下的煤焦异相促还原NO反应更易发生。各组分的吸附顺序对HCN异相还原NO的反应有明显的影响;在典型再燃温度下,NO先吸附时煤焦表面的异相还原反应速率常数为5.28×10~(10),比HCN先吸附时最快反应路径的反应速率常数大一个数量级。煤焦对NO还原具有显著的催化作用;煤焦表面作为NO的还原反应位点,对反应气体具有明显的活化作用。
[Abstract]:The mechanism of HCN reduction of no catalyzed by homogeneous phase and char was studied by using the density functional theory of quantum chemistry. The kinetic parameters of the reaction were calculated. The results show that the activation energy of homogeneous reduction reaction is 306 KJ / mol, while that of no reduction catalyzed by coal char is 136 KJ / mol. At typical reburning temperature of 1 400 K, the reaction rate of heterogeneous reduction of no by HCN is slightly lower than that by heterogeneous reduction of no from coal char. The heterogeneous reduction of no in coal char with HCN is more likely than that in coal char with CO. The adsorption order of each component has a significant effect on the reaction of HCN heterogeneous reduction of no. At typical reburning temperature, the rate constant of heterogeneous reduction reaction on the surface of coal char is 5.28 脳 10 ~ (10) ~ 10 ~ (10), which is an order of magnitude larger than that of the fastest reaction path when HCN is first adsorbed. Coal char can catalyze the reduction of no, and the surface of char, as the site of no reduction reaction, can activate the reaction gas obviously.
【作者单位】：华北电力大学能源动力与机械工程学院;
【基金】：中央高校基本科研业务费专项资金(2017XS121)资助~~
【分类号】：O643.31

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