氢气还原硝酸盐的理论研究  

Theoretical Study on Hydrogen Reduction of Nitrate

作　　者：李倩[1] 郭大为[1] 周涵[1] 

机构地区：[1]中国石化石油化工科学研究院,北京100083

出　　处：《石油学报（石油加工）》2013年第3期427-432,共6页Acta Petrolei Sinica(Petroleum Processing Section)

基　　金：催化裂化烟气同时脱硫脱氮的研究项目(R08063)资助

摘　　要：从烟气中NOx在吸附剂表面形成硝酸盐的事实出发,结合理论计算研究了硝酸盐被还原的微观反应过程。以H2为还原剂、Al(NO3)3为模型化合物,采用密度泛函方法得到的计算结果显示,H2还原Al(NO3)3的反应是分步进行的,H2吸收热量,解离成H·,H·将Al(NO3)3还原为Al(OH)3和NO,然后NO进入气相与H2反应生成N2。H2解离成H·的反应需要445.43kJ/mol的能量,翻越反应能垒需要586.80kJ/mol,是整个反应的控速步骤。除H2离解形成H·反应之外的其余步骤均为放热反应。From the fact that the NOx in flue gas was adsorbed on the surface of adsorbents in the form of nitrate, the micro mechanism of H2 reduction of nitrate was studied with theoretical calculations by using density functional method, in which H2 was used as reducing agent, AI（NOa）a as model compound. The results of thermodynamics and dynamics indicated that the procedures of H2 reduction of nitrate were performed by separated steps. Firstly, the H2 absorbed heat and decomposed into hydrogen radical （H·）. Then Al（NO3）3 reacted with H·and converted into AI（OH）a and NO. Finally NO was reducted by H2 to N2 in gas stream. The reaction energy of H2 to H·was 445.43 kJ/mol with the energy barrier of 586.80 kJ/mol, so the conversion of H2 to H· was the key step in the reduction, apart from which the remaining steps were exothermic reactions.

关 键 词：氢气 硝酸盐 还原 反应机理 

分 类 号：O642.12[理学—物理化学]