NO与SH自由基反应机理及动力学研究
Study on reaction mechanism and kinetics of NO and SH radical
郝昊 1周璐 1史韶旭 1马红和1
作者信息
- 1. 太原理工大学电气与动力工程学院,太原 030024
- 折叠
摘要
为了探究深度调峰时,燃煤发电机组运行中氮组分与硫组分交互作用对硫组分演化的影响,研究了 NO与SH自由基的详细反应机理.采用B3LYP/6-311++G(d,p)方法优化了 SH自由基与NO反应路径上各个驻点的几何构型,并通过IRC验证了反应路径的正确性.在CCSD(T)/def2-TZVPP水平上对反应路径上各个驻点进行了能量计算,通过频率矫正和零点能矫正得到了反应在单重态和三重态上的势能面.计算结果表明,反应共有八条反应通道和三种可能产物,分别为P1(SN+OH)、P2(3SO+3NH)、P3(3S+HNO).其中通道(7)(R→3IM8→3IM9→P1)为该反应的优势通道,反应的主要产物为P1,根据传统过渡态理论与变分过渡态理论并结合隧道矫正计算了该反应通道在298～2000 K范围内的反应速率常数,在此温度范围内反应速率常数三参数拟合为kCVT/Eckart=1.203 × 10-2T4.25exp(-108.29/RT)cm3.mole-cule-1·s-1,具有正温度系数效应.计算得到的速率常数与文献值吻合较好,适用的温度范围更广,所得的动力学参数和热力学数据可以用于燃烧中硫演化机制的建立.
Abstract
In order to explore the influence of interaction between nitrogen and sulfur components on the evolu-tion of sulfur components in the operation of coal-fired power generation units during deep peak shaving,the detailed reaction mechanism of NO and SH radical was studied.B3LYP/6-311++G(d,p)method was used to optimize the geometry of all stationary species on the reaction path between SH radical and NO,and IRC verified the correctness of the reaction path.At the CCSD(T)/def2-TZVPP level,the energy of each stationary point on the reaction path was calculated,and the potential energy surfaces of the reaction in the singlet state and trip-let state were obtained by frequency correction and zero-point energy correction.The calculation results show that there are eight reaction paths and three possible products,respectively P1(SN+OH),P2(3SO+3NH),P3(3S+HNO).The channel(7)(R →3IM8→3IM9→P1)is the dominant channel of this reaction,and the main product of the reaction is P1.The reaction rate constants of this reaction channel in the range of 298～2000 K were calculated according to the traditional transition state theory and the variable transition state theory and com-bined with tunnel correction,and the three parameters of the reaction rate constant were fitted as kCVT/Eckart=1.203 x 10-2T4 25exp(-108.29/RT)cm3·molecule-1·s-1 with a positive temperature coefficient effect.The calculated rate constants are in good agreement with literature values and apply to a wider temperature range,and the resulting kinetic parameters and thermodynamic data can be used for the establishment of the sulfur evolution mechanism in combustion.
关键词
SH自由基/NO/反应机理/速率常数/密度泛函理论/深度调峰Key words
SH radical/NO/Reaction mechanism/Rate constant/Density functional theory/Deep peaking shaving引用本文复制引用
基金项目
山西省基础研究计划(20210302123199)
山西省科技重大专项(20201102006)
出版年
2024
国家科技期刊平台
NSTL
维普
万方数据